EXHIBIT 5.1

		Hogan Lovells US LLP Columbia Square 555 Thirteenth Street, NW Washington, DC 20004 T +1 202 637 5600 F +1 202 637 5910 www.hoganlovells.com

December 12, 2017

Board of Directors

Webster Financial Corporation

145 Bank Street

Waterbury, CT 06702

Ladies and Gentlemen:

We are acting as counsel to Webster Financial Corporation, a Delaware corporation (the “Company”), in connection with the issuance and sale of 6,000,000 depositary shares (the “Depositary Shares”), each representing 1/1,000^th of a share of the Company’s 5.25% Series F Non-Cumulative Perpetual Preferred Stock, par value $0.01 per share and a liquidation preference of $25,000 per share (the “Underlying Preferred Stock), pursuant to a prospectus supplement dated December 5, 2017 and the accompanying prospectus dated December 17, 2014 (such documents, collectively, the “Prospectus”) that form part of the Company’s effective registration statement on Form S-3 (File No. 333-201026) (the “Registration Statement”), the Underwriting Agreement, dated as of December 5, 2017, by and among the Company, Merrill Lynch, Pierce, Fenner & Smith Incorporated, Wells Fargo Securities, LLC, J.P. Morgan Securities LLC and Citigroup Global Markets Inc., as representatives of the Underwriters named in Schedule I to the Underwriting Agreement (the “Underwriting Agreement”), and the Deposit Agreement, dated as of December 12, 2017, by and among the Company, Broadridge Corporate Issuer Solutions, Inc. and the holders from time to time of the depositary receipts described therein (the “Deposit Agreement”). This opinion letter is furnished to you at your request to enable you to fulfill the requirements of Item 601(b)(5) of Regulation S-K, 17 C.F.R. § 229.601(b)(5), in connection with the Registration Statement.

For purposes of this opinion letter, we have examined copies of such agreements, instruments and documents as we have deemed an appropriate basis on which to render the opinions hereinafter expressed. In our examination of the aforesaid documents, we have assumed the genuineness of all signatures, the legal capacity of all natural persons, the accuracy and completeness of all documents submitted to us, the authenticity of all original documents, and the conformity to authentic original documents of all documents submitted to us as copies (including pdfs). As to all matters of fact, we have relied on the representations and statements of fact made in the documents so reviewed, and we have not independently established the facts so relied on. This opinion letter is given, and all statements herein are made, in the context of the foregoing.

This opinion letter is based as to matters of law solely on the applicable provisions of the Delaware General Corporation Law, as amended, as currently in effect. We express no opinion herein as to any other laws, statutes, ordinances, rules, or regulations. As used herein, the term “Delaware General Corporation Law, as amended” includes the statutory provisions contained therein, all applicable provisions of the Delaware Constitution and reported judicial decisions interpreting these laws.

Based upon, subject to and limited by the foregoing, we are of the opinion that (i) the shares of Underlying Preferred Stock represented by the Depositary Shares are validly issued, fully paid and non-assessable

and (ii) the Depositary Shares are validly issued, fully paid and non-assessable and the holders of the Depositary Shares are entitled to the rights specified in the Deposit Agreement.

Hogan Lovells US LLP is a limited liability partnership registered in the District of Columbia. “Hogan Lovells” is an international legal practice that includes Hogan Lovells US LLP and Hogan Lovells International LLP, with offices in: Alicante Amsterdam Baltimore Beijing Berlin Brussels Caracas Colorado Springs Denver Dubai Dusseldorf Frankfurt Hamburg Hanoi Ho Chi Minh City Hong Kong Houston London Los Angeles Madrid Miami Milan Moscow Munich New York Northern Virginia Paris Philadelphia Prague Rome San Francisco Shanghai Silicon Valley Singapore Tokyo Ulaanbaatar Warsaw Washington DC Associated offices: Budapest Jakarta Jeddah Riyadh Zagreb. For more information see www.hoganlovells.com

This opinion letter has been prepared for use in connection with the filing by the Company of a Current Report on Form 8-K, which Form 8-K will be incorporated by reference into the Registration Statement and Prospectus, and speaks as of the date hereof. We assume no obligation to advise you of any changes in the foregoing subsequent to the effective date of the Registration Statement.

We hereby consent to the filing of this opinion letter as Exhibit 5.1 to the above-described Form 8-K and to the reference to this firm under the caption “Legal Matters” in the Prospectus. In giving this consent, we do not thereby admit that we are an “expert” within the meaning of the Securities Act of 1933, as amended.

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