Joseph Buell Ely was an American lawyer and Democratic politician from Massachusetts. As a conservative Democrat, Ely was active in party politics from the late 1910s, helping to build, in conjunction with David I. Walsh, the Democratic coalition that would gain an enduring political ascendancy in the state.

From 1931 to 1935, he served as the 52nd Governor. He was opposed to the federal expansion of the New Deal, and was a prominent intra-party voice in opposition to the policies of Franklin Delano Roosevelt. In 1944 he made a brief unsuccessful bid for the Democratic presidential nomination.