Joseph Hartwell Williams (February 15, 1814 – July 19, 1896) was an American politician who served as the 27th Governor of Maine from 1857 to 1858.

Williams was born in Augusta (in modern-day Maine, then a part of Massachusetts) on February 15, 1814.

Hannibal Hamlin, the Governor of Maine at the time, resigned on February 25, 1857, to accept the position of United States Senator.

Williams, president of the senate at the time, became the new governor of the state.

After leaving office, Williams served as a member of the Maine House of Representatives from 1864 to 1866.