Eldon Brooks Mahon (April 9, 1918 – December 3, 2005) was a United States federal judge.

Born in Loraine, Texas, Mahon received a B.A. from McMurry College in 1939 and an LL.B. from the University of Texas School of Law in 1942. He was in the United States Army Air Corps from 1942 to 1945. He was a law clerk, Hon. J. E. Hickman, Texas State Supreme Court from 1945 to 1946. He was a County attorney of Mitchell County, Texas in 1947. He was a State district attorney of Texas 32nd Judicial District from 1948 to 1960. He was a judge on the Texas State District Court, 32nd Judicial District from 1961 to 1963. He was a vice president of Texas Electric Service Company (TESCO) from 1963 to 1964. He was in private practice in Abilene, Texas from 1964 to 1968. He was the United States Attorney for the Northern District of Texas from 1968 to 1972.

Mahon was a federal judge on the United States District Court for the Northern District of Texas. Mahon was nominated by President Richard Nixon on June 23, 1972, to a seat vacated by Joe Ewing Estes. He was confirmed by the United States Senate on June 28, 1972, and received his commission on July 3, 1972. He assumed senior status on October 1, 1989. Mahon served in that capacity until his death, in Fort Worth, Texas.