Thomas Swan Trumbull (February 15, 1835 - March 30, 1865) was a lawyer in New York and a distinguished artillery officer in the American Civil War.
Trumbull was born in Stonington, Connecticut, on February 15, 1835 as the son of Gurdon Trumbull and Sarah Swan. On the removal of his father to Hartford, Connecticut, he finished his preparatory education there and entered the law office of Thomas C. Perkins as a student. He subsequently graduated from Harvard Law School and commenced practice of his profession in New York. When the American Civil War began, he relinquished his business and volunteered in the Seventh New York regiment; however, due to enrollment, he enlisted as a private in the Third regiment with Colonel Woodhouse. Shortly after he was transferred to the First Connecticut heavy artillery, he rendered distinguished service to his country, exhibiting rare skill as an artillery officer. He participated in major battles in VIrginia and was promoted to be Major on the recommendation of General Robert O. Tyler. He was greatly injured in constitution by the hardships of the Peninsula campaign, and fell ill towards the end.
Trumbull died on March 30, 1865 in Washington, D.C., at 30 years old. He had been dangerously ill for some time, and the news of his death was not therefore entirely unexpected.