1891 U.S. National Championships – Men's singles
| Men's singles | |
|---|---|
| 1891 U.S. National Championships | |
| Champion | Oliver Campbell |
| Runner-up | Clarence Hobart |
| Score | 2–6, 7–5, 7–9, 6–1, 6–2 |
Defending champion Oliver Campbell defeated Clarence Hobart in the challenge round, 2–6, 7–5, 7–9, 6–1, 6–2 to win the men's singles tennis title at the 1891 U.S. National Championships.