James Leo Ryan (born November 19, 1932) is an inactive senior United States circuit judge of the United States Court of Appeals for the Sixth Circuit.

Ryan served as a law specialist in the United States Navy and was assigned to the Judge Advocate General and duty with the United States Marine Corps.

Upon his release from active duty in 1960, he continued to serve in the Judge Advocate General's Corps of the United States Naval Reserve and, in 1992, retired from the Naval Reserve as a military judge with the rank of captain.

He was an adjunct professor at the Thomas M. Cooley Law School in Lansing, Michigan, from 1979 to 1985.

[1] Ryan was nominated by President Ronald Reagan on September 9, 1985, to a seat on the United States Court of Appeals for the Sixth Circuit vacated by Judge George Clifton Edwards Jr.