The 1926 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 16 until August 23 while the men's tournament ran from September 13 until September 18. It was the 46th staging of the U.S. National Championships and the fourth Grand Slam tennis event of the year.

René Lacoste defeated Jean Borotra 6–4, 6–0, 6–4

Molla Bjurstedt Mallory defeated Elizabeth Ryan 4–6, 6–4, 9–7

Richard Norris Williams / Vincent Richards defeated Bill Tilden / Alfred Chapin 6–4, 6–8, 11–9, 6–3

Elizabeth Ryan / Eleanor Goss defeated Mary K. Browne / Charlotte Chapin 3–6, 6–4, 12–10

Elizabeth Ryan / Jean Borotra defeated Hazel Hotchkiss Wightman / René Lacoste 6–4, 7–5

• Official US Open website