Oliver Henry Welf
- Bats Right, Throws Left
- Height 5' 9", Weight 160 lb.
- School Ohio State University
- High School Glenville High School
- Debut August 30, 1916
- Final Game August 30, 1916
- Born January 17, 1889 in Cleveland, OH USA
- Died June 15, 1967 in Cleveland, OH USA
Ollie Welf appeared in one game in the majors on August 30, 1916 for his hometwon Cleveland Indians. He had no at-bats or walks, and he did not appear in the field. He was 27 at the time, one year younger than team star Tris Speaker who was playing his first year with the team.
He was one of the first players to come out of Ohio State University. He is recorded as having attended there during the period 1908-1916.