Thomas Ambrose Masterson (December 10, 1927 – June 15, 2000) was a United States federal judge.
Born in Philadelphia, Pennsylvania, Masterson received a B.A. from Harvard University in 1949 and an LL.B. from the University of Pennsylvania Law School in 1952. He was an Attorney at the U.S. Department of Justice in Washington, DC from 1952 to 1953. He was a volunteer defender in Philadelphia in 1953. He was in private practice in Philadelphia and an instructor at Seton Hall University School of Law from 1953 to 1956. He became assistant District Attorney of Philadelphia 1956 and was a Deputy city solicitor from 1956 to 1960. He was in private practice in Philadelphia from 1973 to 2000.
Masterson was a federal judge on the United States District Court for the Eastern District of Pennsylvania. Masterson was nominated by President Lyndon B. Johnson on January 16, 1967, to a new seat created by 80 Stat. 75. He was confirmed by the United States Senate on June 12, 1967, and received his commission on June 15, 1967. Masterson served in that capacity until November 16, 1973, due to resignation.
He died in Bryn Mawr, Pennsylvania.