W. Ralph "Pest" Welch (January 13, 1907 – September 15, 1974) was an American football player and coach. He served as the head coach at the University of Washington from 1942 to 1947, compiling a record of 27–20–3. Welch led his 1943 Washington squad to the Rose Bowl, where they lost to USC, 29–0. He played college football at Purdue University as a halfback under head coach James Phelan, whom he followed to Washington as an assistant in 1930.