Thomas Buchanan (November 19, 1808 – September 3, 1841) was an American politician and diplomat who served as the first official governor of Liberia for the American Colonization Society.

He was a relative of James Buchanan, who later became the 15th president of the United States.

He worked first as an administrator in Grand Bassa before moving to Monrovia in 1839.

On April 1, Buchanan was appointed as the first governor of the colony, serving until his death on September 3, 1841.

[3] He is the namesake of Buchanan, Liberia, the seat of Grand Bassa County.