The 1925 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 women's tournament was held from August 17 until August 24 while the men's tournament ran from September 14 until September 19. It was the 45th staging of the U.S. National Championships and the fourth Grand Slam tennis event of the year.
See main article: 1925 U.S. National Championships – Men's singles. 
Bill Tilden defeated Bill Johnston 4–6, 11–9, 6–3, 4–6, 6–3
See main article: 1925 U.S. National Championships – Women's singles. Helen Wills defeated 
Kitty McKane 3–6, 6–0, 6–2
Richard Norris Williams / Vincent Richards defeated 
Gerald Patterson / Jack Hawkes 6–2, 8–10, 6–4, 11–9
Mary Browne / Helen Wills defeated May Sutton Bundy / Elizabeth Ryan 6–4, 6–3
Kitty McKane / Jack Hawkes defeated Ermyntrude Harvey / Vincent Richards 6–2, 6–4