The 1931 U.S. National Championships (now known as the US Open) was a tennis tournament that took place on the outdoor grass courts at the West Side Tennis Club, Forest Hills in New York City, United States. The tournament ran from September 3 until September 10. It was the 51st staging of the U.S. National Championships and the fourth Grand Slam tennis event of the year.[1]
| 1931 U.S. National Championships | |
|---|---|
| Date | September 3–10 (M) August 15–20 (W) |
| Edition | 51st |
| Category | Grand Slam (ITF) |
| Surface | Grass / Outdoor |
| Location | Forest Hills, Queens New York City, United States |
| Venue | West Side Tennis Club |
| Champions | |
| Men's singles | |
 Ellsworth Vines | |
| Women's singles | |
| Helen Wills Moody | |
| Men's doubles | |
| Wilmer Allison / John Van Ryn | |
| Women's doubles | |
 Betty Nuthall / Eileen Bennett Whittingstall | |
| Mixed doubles | |
| Betty Nuthall / George Lott | |
Finals edit
Men's singles edit
Ellsworth Vines defeated George Lott 7–9, 6–3, 9–7, 7–5
Women's singles edit
Helen Wills Moody defeated Eileen Bennett Whittingstall 6–4, 6–1
Men's doubles edit
Wilmer Allison / John Van Ryn defeated 
Gregory Mangin / Berkeley Bell 6–4, 8–6, 6–3 [2]
Women's doubles edit
Betty Nuthall / Eileen Bennett Whittingstall defeated Helen Jacobs / Dorothy Round 6–2, 6–4 [3]
Mixed doubles edit
Betty Nuthall / George Lott defeated Anna McCune Harper / Wilmer Allison 6–3, 6–3 [4]