Walter Pettus Gewin (December 9, 1908 – May 15, 1981) was a United States federal judge.
Born in Nanafalia, Alabama, Gewin received an A.B. from Birmingham-Southern College in 1930, a B.L.S. from Emory University in 1932, and an LL.B. from the University of Alabama School of Law in 1935. He was in private practice in Birmingham, Alabama from 1935 to 1936. He was in private practice in Greensboro, Alabama from 1936 to 1951. He was a Prosecuting attorney of Hale County, Alabama from 1942 to 1951. He was in private practice in Tuscaloosa, Alabama from 1951 to 1961.
Gewin was a federal judge on the United States Court of Appeals for the Fifth Circuit. Gewin received a recess appointment from John F. Kennedy on October 5, 1961, to a new seat created by 75 Stat. 80; nominated on January 15, 1962. He was confirmed by the United States Senate on February 5, 1962, and received his commission on February 9, 1962. He assumed senior status on November 1, 1976. Gewin served in that capacity until May 15, 1981, due to his death.
He died in Tuscaloosa, Alabama.