James Gideon Monahan (January 12, 1855 – December 5, 1923) was a U.S. Representative from Wisconsin. Born at Willow Springs, near Darlington, Wisconsin, Monahan attended the common schools and graduated from the Darlington High School in 1875. He studied law and was admitted to the bar in 1878. He commenced practice in Mineral Point, Wisconsin.He returned to Darlington in 1880. He served as district attorney of Lafayette County 1880-1884.From 1883 till 1919 he was editor and owner of the Darlington Republican Journal.He served as delegate to the Republican National Convention in 1888.He also served as collector of internal revenue for the second Wisconsin district 1900-1908.