Peter Jo Messitte (born 1941) is a United States federal judge.
Born in Washington, D.C., Messitte received a B.A. from Amherst College in 1963 and a J.D. from the University of Chicago Law School in 1966. He was a Peace Corps volunteer in São Paulo, Brazil from 1966 to 1968. He was in private practice in [[Washington, D.C.],] from 1969 to 1971. He was in private practice in Chevy Chase, Maryland from 1971 to 1985. He was an Associate judge, Circuit Court, Montgomery County, Maryland from 1985 to 1993.
Messitte was a federal judge on the United States District Court for the District of Maryland. Messitte was nominated by President Bill Clinton on August 6, 1993, to a seat vacated by Joseph C. Howard, Sr. He was confirmed by the United States Senate on October 18, 1993, and received his commission on October 20, 1993. He assumed senior status on September 1, 2008.