| Harry Dayhoff | |
| Birth Place: | Gettysburg, Pennsylvania, U.S. |
| Death Place: | Harrisburg, Pennsylvania, U.S.[1] |
| Position1: | Halfback |
| Position2: | Fullback |
| Position3: | Quarterback |
| Height Ft: | 5 |
| Height In: | 8 |
| Weight Lb: | 170 |
| College: | Bucknell |
| Playing Years1: | 1924 |
| Playing Team1: | Frankford Yellow Jackets |
| Playing Years2: | 1925 |
| Playing Team2: | Pottsville Maroons |
| Career Highlights: |
|
| Nfl: | DAY553720 |
Harry Oscar Dayhoff (May 25, 1896 - February 17, 1963) was a professional football player from Gettysburg, Pennsylvania. He attended Bucknell University and later made his professional debut in the National Football League (NFL) with the Frankford Yellow Jackets in 1924. In 1925 he played for the Pottsville Maroons and won the 1925 Championship with the team before the title was stripped from the team due to a disputed rules violation.