Thomas Lynch Montgomery (March 4, 1862 – October 1, 1929) was an American historian and librarian of the Pennsylvania State Library, Harrisburg. Thomas Lynch Montgomery was born in the Germantown area of Philadelphia, Pennsylvania, March 4, 1862, the son of Oswald Crathorne and Catherine Gertrude (Lynch) Montgomery. He graduated from the University of Pennsylvania in 1884, with the degree of Bachelor of Arts. He was a Republican.