Robert W. Pratt (born 1947) is a United States federal judge.
Born in Emmetsburg, Iowa, Pratt received an A.A. from Iowa Lakes Community College in 1967, a B.A. from Loras College in 1969, and a J.D. from Creighton University School of Law in 1972. He was a Staff attorney of Polk County Legal Aid Society from 1973 to 1974. He was in private practice in Des Moines, Iowa from 1975 to 1997.
On January 7, 1997, Pratt was nominated by President Bill Clinton to a seat on the United States District Court for the Southern District of Iowa vacated by Harold D. Vietor. Pratt was confirmed by the United States Senate on May 23, 1997, and received his commission on May 27, 1997. He became chief judge in 2006.