Eaton Vance Municipal Bond Fund

This proxy statement is furnished in connection with the solicitation of proxies by the Board of Trustees of Eaton Vance Municipal Bond Fund (the “Fund”). The proxies will be voted at the Annual Meeting of Shareholders of the Fund and at any adjournments or postponements thereof (the “Annual Meeting”). The Annual Meeting will be held on Tuesday, August 18, 2026 at 11:30 a.m. (Eastern Time) at the principal office of the Fund, One Post Office Square, Boston, Massachusetts 02109, as discussed further herein. The Annual Meeting will be held for the purposes set forth in the accompanying notice. This proxy statement and the enclosed proxy card(s) are first being sent or given to shareholders on or about June 25, 2026.

The Board of Trustees of the Fund (the “Board” or the “Board of Trustees”) has fixed the close of business on June 4, 2026 as the record date for the determination of the shareholders entitled to notice of and to vote at the Annual Meeting and any adjournments or postponements thereof. As of June 4, 2026, there were 51,372,599 common shares of beneficial interest, $0.01 par value per share (“Common Shares”), of the Fund outstanding. See “Proxy Solicitation, Tabulation and Voting Requirements” below for additional information. To the knowledge of the Fund, as of June 4, 2026: (i) no shareholder owned 5% or more of the outstanding Common Shares of the Fund, and (ii) the Trustees and executive officers of the Fund, individually and as a group, owned beneficially less than 1% of the outstanding Common Shares of the Fund.

Shareholders as of the close of business on the record date of June 4, 2026 are entitled to attend and vote at the Annual Meeting. All properly executed proxies received prior to the Annual Meeting will be voted at the Annual Meeting. Each proxy will be voted in accordance with its instructions; if no instruction is given, an executed proxy will authorize the persons named on the proxy card enclosed as proxies, or any of them, to vote FOR the election of each Trustee. An executed proxy delivered to the Fund is revocable by the person giving it, prior to its exercise, by a signed writing filed with the Fund’s Secretary, by executing and delivering a later dated proxy, or by attending the Annual Meeting and voting the shares at the Annual Meeting. Merely attending the Annual Meeting will not revoke a previously executed proxy. If you hold Fund shares through an intermediary (such as a broker, bank, adviser or custodian), please consult with the intermediary regarding your ability to revoke voting instructions after they have been provided.

If you are a record holder of Fund shares and plan to attend the Annual Meeting, you must show a valid photo identification (such as a driver’s license) to gain admission to the Annual Meeting. Please call 1-800-262-1122 for information on how to obtain directions to be able to attend and vote at the Annual Meeting.

If you hold Fund shares through an intermediary and plan to attend and vote at the Annual Meeting, you will be required to show a valid photo identification and your authority to vote your shares (referred to as a “legal proxy”) to gain admission to the Annual Meeting. As described above, you must contact your intermediary to obtain a legal proxy for your shares.