1931 U.S. National Championships (tennis)

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.

Men's singles
🇺🇸 Ellsworth Vines defeated 🇺🇸 George Lott 7–9, 6–3, 9–7, 7–5

Women's singles
🇺🇸 Helen Wills Moody defeated 🇬🇧 Eileen Bennett Whittingstall 6–4, 6–1

Men's doubles
🇺🇸 Wilmer Allison / 🇺🇸 John Van Ryn defeated 🇺🇸 Gregory Mangin / 🇺🇸 Berkeley Bell 6–4, 8–6, 6–3

Women's doubles
🇬🇧 Betty Nuthall / 🇬🇧 Eileen Bennett Whittingstall defeated 🇺🇸 Helen Jacobs / 🇬🇧 Dorothy Round 6–2, 6–4

Mixed doubles
🇬🇧 Betty Nuthall / 🇺🇸 George Lott defeated 🇺🇸 Anna McCune Harper / 🇺🇸 Wilmer Allison 6–3, 6–3