Thomas J. Tolan (October 22, 1830 – January 31, 1883) was an American architect.
He was born in Carrollton, Ohio to James and Elizabeth Crabbs Tolan. Like his father, he began working as a marble cutter in Delphos, Ohio. He married Harriett Todd Skinner on October 24, 1853.
At some point in his life he made the jump from being a marble craftsman to an architect. In 1874, he moved his family and architectural practice to Fort Wayne, Indiana. The firm was known as T.J. Tolan & Son, Architects. His son Brentwood S. Tolan trained under with him and continued the practice after his death. Tolan and his son were noted for designing municipal and local government buildings, including courthouses and jails. In addition they designed some churches and fraternal buildings. His most notable work included the courthouses in Van Wert, Ohio, Cambridge, Illinois, Bloomfield, Iowa, and Rockville, Lagrange, and Warsaw, Indiana.
Tolan died while traveling on business in Chicago, Illinois. He is buried in Delphos, Ohio.