Donald W. Molloy (born 1946) is a senior United States federal judge on the United States District Court for the District of Montana.
Born in Butte, Montana, Molloy received a B.A. from the University of Montana in 1968 and a J.D. from the University of Montana School of Law in 1976. He was in the United States Navy, Naval Aviation from 1968 to 1973. He was a law clerk, Hon. James Battin, U.S. District Court, District of Montana from 1976 to 1978. He was in private practice in Billings, Montana from 1978 to 1995.
Molloy was nominated to the District Court by President Bill Clinton on December 21, 1995, to a seat vacated by Paul Gerhart Hatfield. He was confirmed by the United States Senate on July 18, 1996, and received his commission on August 1, 1996. He served as chief judge from 2001 to 2008, and assumed senior status on August 16, 2011.