Walter Roe Mansfield (July 1, 1911 – January 8, 1987) was an American federal judge in the United States.
Judge Mansfield was the son of Boston Mayor Frederick W. Mansfield and Helen Elizabeth (Roe) Mansfield.
Mansfield received his A.B. from Harvard College in 1932 and his LL.B. from Harvard Law School in 1935 before working as a lawyer in private practice in New York City for three decades, interrupted by two years as an Assistant United States Attorney and service in the United States Marine Corps during World War II from 1942-1946.
In 1966, President Lyndon B. Johnson nominated Mansfield to serve as a judge of the United States District Court for the Southern District of New York. Five years later, President Richard M. Nixon promoted Mansfield to an appellate judgeship on the United States Court of Appeals for the Second Circuit. Mansfield was an active judge of the Second Circuit for ten years, from 1971 to 1981. He took senior status in 1981 but continued to hear cases until his death in 1987.
Mansfield passed after suffering a stroke, at the age of 75, while on vacation in Christchurch, New Zealand.