SMTB Smithtown Bancorp (MM)

SUMMARY

This summary highlights selected information from this proxy statement/prospectus. It does not contain all of the information that may be important to you. We urge you to read carefully the entire document and the other documents to which this proxy statement/prospectus refers in order to fully understand the merger and the related transactions. See “Where You Can Find More Information” beginning on page 202. Each item in this summary refers to the page of this proxy statement/prospectus on which that subject is discussed in more detail. Unless otherwise indicated in this proxy statement/prospectus or the context otherwise requires, all references in the proxy statement/prospectus to “People’s United” refer to People’s United Financial, Inc. All references to the “Company” or to “Smithtown Bancorp” refer to Smithtown Bancorp, Inc.

The Parties to the Merger (Page 28)

People’s United

People’s United is the holding company for People’s United Bank. At June 30, 2010, People’s United had assets of $22 billion, deposits of $16 billion and stockholders’ equity of $5 billion. A diversified financial services company founded in 1842, People’s United provides consumer, commercial, insurance, retail investment and wealth management and trust services to personal and business banking customers. The address of People’s United’s principal executive offices is 850 Main Street, Bridgeport, Connecticut 06604, and its telephone number is (203) 338-7171.

Smithtown Bancorp

Smithtown Bancorp is a New York corporation, incorporated in 1984, which is registered as a bank holding company under the Bank Holding Company Act of 1956, as amended, and parent of Bank of Smithtown, a New York State-chartered commercial bank with 30 branches. As of June 30, 2010, Smithtown Bancorp and its subsidiaries had consolidated total assets of $2.3 billion, deposits of $1.8 billion and stockholders’ equity of $95.6 million. Smithtown Bancorp had 275 full-time and 50 part-time employees as of June 30, 2010.

The Merger and Bank Merger (Page 33)

Smithtown Bancorp’s board of directors proposes the merger of Smithtown Bancorp with and into People’s United, with People’s United as the surviving corporation. We refer to this merger as the merger. Upon completion of the merger, the separate existence of Smithtown Bancorp will terminate, and Smithtown Bancorp common stock will be cancelled and no longer publicly traded. The Agreement and Plan of Merger, which we refer to as the merger agreement, is attached to this proxy statement/prospectus as Annex A and is incorporated herein by reference. Please carefully read the merger agreement as it is the legal document that governs the merger. Simultaneously with the merger, Bank of Smithtown, the bank subsidiary of Smithtown Bancorp, will merge with and into People’s United Bank, the bank subsidiary of People’s United. We refer to this merger as the bank merger. We currently expect to complete these mergers in the fourth quarter of 2010.

What Smithtown Bancorp Stockholders Will Receive in the Merger (Page 65)

Upon completion of the merger, each outstanding share of Smithtown Bancorp common stock will be converted into the right to receive, at the election of each holder of record as of the record date of such share and subject to proration in the circumstances described below, either cash or shares of People’s United common stock. To make a valid election, holders of record as of the record date of Smithtown Bancorp’s common stock must submit a properly completed election form to the exchange agent by 5:00 p.m., New York City time, on the later of the date of the special meeting and the date that People’s United and Smithtown Bancorp believe to be as near as practicable to five business days prior to the anticipated date of completion of the merger or such other time as People’s United and Smithtown Bancorp may agree. Holders of Smithtown Bancorp common stock may specify different elections with respect to different shares that they hold (for example, the owner of 100 shares of

Smithtown Bancorp common stock can make a cash election with respect to 50 shares and a stock election with respect to the other 50 shares). In the event of proration, Smithtown Bancorp stockholders may receive a portion of the merger consideration in a form other than that which they elected.

The implied value of the merger consideration will fluctuate with the market price of People’s United common stock and will be determined based on the average closing price of People’s United common stock on the NASDAQ for the five trading days ending the day before the completion of the merger. (You may contact Phoenix Advisory Partners, LLC, Smithtown Bancorp’s proxy solicitor, at (866) 351-1539 to obtain current information regarding the implied value of the merger consideration.) As explained in more detail in this document, whether Smithtown Bancorp stockholders make a cash election or a stock election, the value of the consideration that they receive as of the date of completion of the merger will be substantially the same and will be based on the average closing price of People’s United common stock used to calculate the merger consideration.

As an example, if the average of the closing prices of Peoples’ United common stock on the NASDAQ for the five trading days ending the day before the completion of the merger is $14.00, each share of Smithtown Bancorp common stock would entitle its holder to receive either $4.00 in cash or 0.286 of a share of People’s United common stock, subject to possible proration. We will compute the actual amount of cash and number of shares of People’s United common stock that each Smithtown Bancorp stockholder will receive in the merger using the formula contained in the merger agreement. For a summary of the formula contained in the merger agreement, see “The Merger Agreement—Consideration To Be Received in the Merger” beginning on page 65.

Set forth below is a table showing the consideration that a Smithtown Bancorp stockholder would receive in a cash election, on the one hand, or in a stock election, on the other hand, under the merger consideration formula if the actual average of the closing prices of People’s United common stock on the NASDAQ for the five trading days ending the day before the completion of the merger were equal to each of the hypothetical average closing prices shown in the table. The merger consideration formula reflected in the table below yields a per-share value for Smithtown Bancorp common stock equal to the sum of (a) $2.00 plus (b) 0.143 multiplied by the hypothetical average closing prices for People’s United common stock shown in the table. The stock consideration reflected in the table below is equal to the quotient obtained by dividing (x) the value determined in accordance with the preceding sentence by (y) the hypothetical average closing prices for People’s United common stock shown in the table. The table does not reflect the fact that cash will be paid instead of fractional shares. As described below, regardless of whether you make a cash election or a stock election, you may nevertheless receive cash, stock or a mix of cash and stock due to proration and adjustment.

Based on the average closing sale price of People’s United common stock for the five trading day period ended on October 11, 2010, the last practicable trading day before distribution of this proxy statement/prospectus, which was $13.34, a Smithtown Bancorp stockholder would receive either $3.91 in cash or 0.293 of a share of People’s United common stock in exchange for each share of Smithtown Bancorp common stock owned by that stockholder.

The examples above are illustrative only. The value of the merger consideration that Smithtown Bancorp stockholders actually receive will be based on the actual average closing price of People’s United common stock on the NASDAQ for the five trading days ending the day before the completion of the merger, as described below. The actual average closing price may be outside the range of the amounts set forth above, and as a result, the actual value of the merger consideration per share of Smithtown Bancorp common stock may not be shown in the above table.

Regardless of Whether Smithtown Bancorp Stockholders Make a Cash Election or a Stock Election, They May Nevertheless Receive Cash, Stock or a Mix of Cash and Stock (Page 68)

Assuming that none of the outstanding warrants to purchase Smithtown Bancorp’s common stock are exercised prior to the effective time of the merger, the aggregate number of shares of People’s United common stock that will be issued in the merger is approximately 2.14 million, based on the number of shares of Smithtown Bancorp common stock outstanding on the record date of October 8, 2010, and the aggregate amount of cash that will be paid in the merger is approximately $29.9 million. If more Smithtown Bancorp stockholders make valid elections to receive either People’s United common stock or cash than is available as merger consideration under the merger agreement, those Smithtown Bancorp stockholders electing the over-subscribed form of consideration will have the over-subscribed consideration proportionately reduced and substituted with consideration in the other form, despite their election.

What Holders of Smithtown Bancorp Warrants and Equity-Based Awards Will Receive in the Merger (Page 70)

At the effective time of the merger, each outstanding warrant to purchase shares of Smithtown Bancorp common stock will remain outstanding pursuant to the terms of such warrant. After the completion of the merger, each such warrant will entitle the holder to receive upon exercise of such warrant, in accordance with its terms,

the stock consideration applicable to a share of Smithtown Bancorp common stock (without giving effect to any possible proration, as described above).

Prior to the effective time of the merger, all Smithtown Bancorp restricted stock awards will vest, and all of the previously restricted shares will be treated as outstanding Smithtown Bancorp shares for all purposes under the merger agreement, including for purposes of the holders’ right to receive the same merger consideration as all other outstanding shares of Smithtown Bancorp common stock are entitled to receive in the merger.

Accounting Treatment of the Merger (Page 60)

People’s United will account for the merger as a purchase for financial reporting purposes.

Material U.S. Federal Income Tax Consequences of the Merger (Page 57)

The merger is intended to qualify for U.S. federal income tax purposes as a “reorganization” within the meaning of Section 368(a) of the Internal Revenue Code of 1986, as amended, which we refer to as the Code. Therefore, for U.S. federal income tax purposes, as a result of the merger, a U.S. holder of shares of Smithtown Bancorp common stock generally will only recognize gain (but not loss) in an amount not to exceed the cash received as part of the merger consideration but will recognize gain or loss (i) if such holder receives the entirety of its consideration in cash and (ii) with respect to any cash received in lieu of fractional shares of People’s United common stock.

Special Meeting of Smithtown Bancorp Common Stockholders (Page 30)

Smithtown Bancorp will hold its special meeting of common stockholders on November 19, 2010, at 10:00 a.m. local time, at the Sheraton Long Island Hotel, 110 Motor Parkway, Hauppauge, New York 11788. At the special meeting you will be asked to approve the merger agreement and the transactions contemplated by the merger agreement and to approve adjournment of the special meeting, if necessary to solicit additional proxies in favor of the merger agreement.

You can vote at the Smithtown Bancorp special meeting of common stockholders if you owned Smithtown Bancorp common stock at the close of business on October 8, 2010. As of that date, there were approximately 14,967,508 shares of Smithtown Bancorp common stock outstanding and entitled to vote, approximately 689,919 of which, or 4.61%, were owned beneficially or of record by directors and officers of Smithtown Bancorp. You can cast one vote for each share of Smithtown Bancorp common stock that you owned on that date.

Opinion of Smithtown Bancorp’s Financial Advisor (Page 39)

Sandler O’Neill & Partners, L.P., which we refer to as Sandler O’Neill, delivered its opinion to Smithtown Bancorp’s board of directors that, as of July 15, 2010 and based upon and subject to the factors and assumptions set forth therein, the merger consideration of 0.143 of a share of People’s United common stock plus $2.00 in cash for each share of Smithtown Bancorp common stock held immediately prior to the merger is fair to the holders of Smithtown Bancorp common stock from a financial point of view.

The full text of the written opinion of Sandler O’Neill, dated July 15, 2010, which sets forth assumptions made, procedures followed, matters considered and limitations on the review undertaken in connection with the opinion, is attached as Annex B. Sandler O’Neill provided its opinion for the information and assistance of Smithtown Bancorp’s board of directors in connection with its consideration of the merger. The Sandler O’Neill opinion is not a recommendation as to how any holder of Smithtown Bancorp common stock should vote with respect to the merger or any other matter. Pursuant to an engagement letter between Smithtown Bancorp and Sandler O’Neill, Sandler O’Neill will receive a fee of $1,000,000 for its services, of which $850,000 is contingent upon completion of the merger. For further information, please see the discussion under the caption “The Merger—Opinion of Smithtown Bancorp’s Financial Advisor,” commencing on page 39.

Recommendation of Smithtown Bancorp’s Board of Directors (Page 38)

Smithtown Bancorp’s board of directors has unanimously adopted and declared advisable the merger agreement and the transactions contemplated by the merger agreement, including the merger, and recommends that Smithtown Bancorp common stockholders vote “FOR” approval of the merger agreement and the transactions contemplated by the merger agreement, including the merger, and “FOR” the approval of the adjournment of the special meeting, if necessary, to solicit additional proxies in favor of the merger agreement and the transactions contemplated by the merger agreement, including the merger.

For more information concerning the background of the merger, the recommendation of Smithtown Bancorp’s board of directors and the reasons for the merger and the recommendation, please see the discussions under “The Merger—Background of the Merger” and “The Merger—Smithtown Bancorp’s Reasons for the Merger; Recommendation,” commencing on page 33 and page 38, respectively.

Interests of Smithtown Bancorp’s Directors and Executive Officers in the Merger (Page 51)

In considering the information contained in this proxy statement/prospectus, you should be aware that Smithtown Bancorp’s executive officers and members of Smithtown Bancorp’s board of directors may have financial interests in the merger that are different from, or in addition to, the interests of Smithtown Bancorp stockholders generally. These additional interests of Smithtown Bancorp’s executive officers and directors may create potential conflicts of interest and cause these persons to view the proposed transaction differently than you may view it as a stockholder.

The independent members of Smithtown Bancorp’s board of directors were aware of these interests and, except for a recently agreed retention award between Smithtown Bancorp’s chief financial officer and People’s United Bank, Smithtown Bancorp’s board of directors took them into account in its decision to declare advisable the merger agreement and the transactions contemplated by the merger agreement, including the merger. For information concerning these interests, please see the discussion under the caption “The Merger—Interests of Smithtown Bancorp’s Directors and Executive Officers in the Merger,” commencing on page 51.

No Solicitation of Alternative Transactions (Page 76)

Smithtown Bancorp has agreed not to initiate, solicit, knowingly encourage or knowingly facilitate the submission of any proposals from third parties regarding acquiring Smithtown Bancorp or its businesses. In addition, Smithtown Bancorp has agreed not to engage in discussions or negotiations with or provide confidential information to a third party regarding acquiring Smithtown Bancorp or its businesses. However, if Smithtown Bancorp receives an unsolicited acquisition proposal from a third party, Smithtown Bancorp may engage in negotiations with or provide confidential information to such third party if, among other steps, the Smithtown Bancorp board of directors concludes in good faith that the proposal constitutes or is reasonably likely to result in a superior proposal to the merger.

Vote Required (Page 30)

The merger agreement and the transactions contemplated by the merger agreement must be approved by the holders of two-thirds of the issued and outstanding common stock of Smithtown Bancorp. The Special Committee of Smithtown Bancorp’s board of directors, appointed to select a record date for the determination of holders of Smithtown Bancorp common stock entitled to notice of and to vote at the special meeting, has fixed the close of business on October 8, 2010 as the record date for determining the Smithtown Bancorp common stockholders entitled to receive notice of and to vote at the special meeting.

Smithtown Bancorp is calling a special meeting of the common stockholders to consider and vote on the proposal to approve the merger agreement and the transactions contemplated by the merger agreement, including the merger.

Regulatory Approvals Required for the Merger (Page 60)

To complete the merger, Smithtown Bancorp and People’s United need the prior approval of the Office of Thrift Supervision. The United States Department of Justice is able to provide input into the approval process of federal banking agencies to challenge the approval on antitrust grounds. Smithtown Bancorp and People’s United have filed all necessary applications and notices with the applicable regulatory authorities. Smithtown Bancorp and People’s United cannot predict, however, whether or when the required regulatory approvals will be obtained.

Conditions to Completion of the Merger (Page 79)

As more fully described in this proxy statement/prospectus and the merger agreement, the completion of the merger depends on a number of mutual conditions being satisfied or waived, including:

Each of People’s United’s and Smithtown Bancorp’s obligations to complete the merger is also separately subject to the satisfaction or waiver of a number of conditions, including:

People’s United and Smithtown Bancorp cannot be certain of when, or if, the conditions to the merger will be satisfied or waived or whether or not the merger will be completed.

Termination of the Merger Agreement (Page 80)

People’s United and Smithtown Bancorp can agree at any time to terminate the merger agreement without completing the merger, even if Smithtown Bancorp stockholders have approved the merger agreement. Also, either of People’s United or Smithtown Bancorp can terminate the merger agreement if:

Additionally, People’s United may terminate the merger agreement if:

Termination Fee (Page 81)

Smithtown Bancorp has agreed to pay to People’s United a termination fee of up to $2,400,000 if the merger agreement is terminated under the circumstances specified in “The Merger Agreement—Termination of the Merger Agreement—Termination Fee,” beginning on page 81.

Amendment or Waiver of Merger Agreement Provisions (Page 82)

People’s United and Smithtown Bancorp may jointly amend the merger agreement, and each of People’s United and Smithtown Bancorp may waive its right to require the other party to comply with particular provisions of the merger agreement.

People’s United may also change the structure of the merger, as long as any such change does not alter or change the amount or kind of merger consideration to be provided under the merger agreement, materially impede or delay completion of the merger, adversely affect the anticipated tax consequences to Smithtown Bancorp stockholders in the merger or result in the bank merger taking place at any time other than simultaneously with the merger. For example, People’s United may decide to merge Smithtown Bancorp into a newly formed wholly owned subsidiary of People’s United.

People’s United Repurchases of its Common Stock

Following the announcement of the execution of the merger agreement and pursuant to its previously reported repurchase plan, People’s United has repurchased shares of its common stock on the open market in reliance on the Rule 10b-18 safe harbor under the Securities Exchange Act of 1934. Since July 15, 2010 through the close of business on October 11, 2010, People’s United has repurchased an aggregate of 1,882,592 shares of its common stock at an average price of $13.29. People’s United may make additional purchases of shares of its common stock prior to the completion of the merger, subject to market conditions and applicable securities laws.

No Appraisal or Dissenters’ Rights (Page 63)

Holders of Smithtown Bancorp common stock are not entitled to appraisal or dissenters’ rights under Section 910 of the New York Business Corporation Law, which we refer to as the NYBCL, in connection with the merger.

Differences Between Rights of People’s United and Smithtown Bancorp Stockholders (Page 85)

As a result of the merger, the holders of Smithtown Bancorp common stock who receive stock consideration will become holders of People’s United common stock. Following the merger, Smithtown Bancorp stockholders who receive stock consideration will have different rights as stockholders of People’s United than as stockholders of Smithtown Bancorp due to differences between the laws of the jurisdictions of incorporation and the different provisions of the certificates of incorporation and bylaws of People’s United and Smithtown Bancorp. For additional information regarding the different rights as stockholders of People’s United than as stockholders of Smithtown Bancorp, see “Comparison of Stockholder Rights” beginning on page 85.

SELECTED CONSOLIDATED HISTORICAL FINANCIAL DATA OF PEOPLE’S UNITED

People’s United is providing the following information to aid you in your analysis of the financial aspects of the merger. People’s United derived the financial information as of and for the fiscal years ended December 31, 2007 through December 31, 2009 from its historical audited financial statements for these fiscal years. People’s United derived the financial information as of and for the fiscal years ended December 31, 2005 and December 31, 2006 from the historical audited financial statements of People’s United Bank for these fiscal years. People’s United derived the financial information as of and for the six months ended June 30, 2009 and June 30, 2010 from its unaudited financial statements, which financial statements include, in the opinion of People’s United’s management, all adjustments, consisting of normal and recurring adjustments, necessary for a fair statement of those results.

On April 16, 2010, People’s United Bank entered into a definitive purchase and assumption agreement with the Federal Deposit Insurance Corporation (the “FDIC”) pursuant to which People’s United Bank assumed all of the deposits, certain assets and the banking operations of Butler Bank. The transaction resulted in the acquisition of approximately $244 million in total assets and approximately $227 million in total deposits. The assets acquired and liabilities assumed were recorded by People’s United at their estimated fair values as of the closing date and People’s United’s results of operations for the six months ended June 30, 2010 include the results of Butler Bank beginning with the closing date.

On February 19, 2010, People’s United completed its acquisition of Financial Federal Corporation (“Financial Federal”), a financial services company providing collateralized lending, financing and leasing services nationwide to small and medium sized businesses. On the closing date, Financial Federal had total assets of $1.28 billion. The assets acquired and liabilities assumed were recorded by People’s United at their estimated fair values as of the closing date and People’s United’s results of operations for the six months ended June 30, 2010 include the results of Financial Federal beginning with the closing date.

The results for the six months ended June 30, 2010 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2010. This information is only a summary, and you should read it in conjunction with People’s United’s consolidated financial statements and the related notes contained in People’s United’s periodic reports filed with the Securities and Exchange Commission that have been incorporated by reference in this proxy statement/prospectus. See “Where You Can Find More Information” beginning on page 202.

SELECTED CONSOLIDATED HISTORICAL FINANCIAL DATA OF SMITHTOWN BANCORP

Smithtown Bancorp is providing the following information to aid you in your analysis of the financial aspects of the merger. Smithtown Bancorp derived the financial information as of and for the fiscal years ended December 31, 2005 through December 31, 2009 from its historical audited financial statements for these fiscal years. Smithtown Bancorp derived the financial information as of and for the six months ended June 30, 2009 and June 30, 2010 from its unaudited financial statements, which financial statements include, in the opinion of Smithtown Bancorp’s management, all adjustments, consisting of normal and recurring adjustments, necessary for a fair statement of those results. The results for the six months ended June 30, 2010 are not necessarily indicative of the results that may be expected for the fiscal year ending December 31, 2010. This information is only a summary, and you should read it in conjunction with Smithtown Bancorp’s consolidated financial statements, related notes, the information provided under the caption “Information about Smithtown Bancorp—Management’s Discussion and Analysis of Financial Condition and Results of Operations,” and other information included in this prospectus and proxy statement.