Chittenden was born in East Guilford in the Colony of Connecticut on January 6, 1730. He married Elizabeth Meigs on October 4, 1749, in Salisbury, Connecticut. The couple had four sons and six daughters while they were living in Connecticut. All the children survived to adulthood. He was a justice of the peace in Salisbury and a member of the Colonial Assembly from 1765 to 1769. He served in Connecticut’s 14th Regiment of Militia from 1767 to 1773, rising to the rank of colonel.

Chittenden moved to the New Hampshire Grants, now Vermont, in 1774, where he was the first settler in the town of Williston. In 1777, a convention was held in Windsor, which drafted Vermont’s first constitution, establishing Vermont as an independent republic. During the American Revolution, Chittenden was a member of a committee empowered to negotiate with the Continental Congress to allow Vermont to join the Union. The Congress deferred the matter in order to not antagonize the states of New York and New Hampshire, which had competing claims against Vermont. During the period of the Vermont Republic, Chittenden served as governor from 1778 to 1789 and 1790 to 1791, and was one of the participants in a series of delicate negotiations with British authorities in Quebec over the possibility of establishing Vermont as a British province.

After Vermont entered the federal Union in 1791 as the fourteenth state, Chittenden continued to serve as governor until his death in 1797.

Chittenden died in Williston on August 25, 1797 and is interred at Thomas Chittenden Cemetery, Williston, Chittenden County, Vermont. Citing Vermont’s tumultuous founding, his epitaph reads “Out of storm and manifold perils rose an enduring state, the home of freedom and unity.”

In 1894, a monument to Chittenden was begun at the entrance to the cemetery in Williston which is named for him; it was dedicated in 1896. An engraved portrait of Chittenden can be found just outside the entrance to the Executive Chamber, the ceremonial office of the governor, at the Vermont State House at Montpelier. The portrait is based on a likeness of one of Chittenden’s grandsons, who was believed to resemble Chittenden. In the late 1990s, a bronze sculpture of Chittenden, which was created by Frank Gaylord, was placed on the grounds of the State House near the building’s west entrance. Another Chittenden statue, also created by Gaylord, was erected in front of the Williston Central School. Chittenden County is named for him, as is the town of Chittenden in Rutland County.