1940 U.S. National Championships – Men's singles
| Men's singles | |
|---|---|
| 1940 U.S. National Championships | |
| Champion | Donald McNeill |
| Runner-up | Bobby Riggs |
| Score | 4–6, 6–8, 6–3, 6–3, 7–5 |
| Draw | 78 |
| Seeds | 10 |
Donald McNeill defeated Bobby Riggs 4–6, 6–8, 6–3, 6–3, 7–5 in the final to win the men's singles tennis title at the 1940 U.S. National Championships.