William Thomas Haines (August 7, 1854 – June 4, 1919) was an American politician and the 49th Governor of Maine.

William Thomas Haines was born in Levant, Maine on August 7, 1854.

As an undergraduate at the University of Maine, he founded the Eternal Companions Society[1] on the Orono Campus in 1875.

In May, 1879, Haines settled at Oakland (then West Waterville), Kennebec County, Maine, and commenced the practice of law.

He served as the attorney general of Maine (1896-1901) and then became a member of the governor’s executive council (1901-1905).