The 1923 U.S. National Championships (now known as the US Open) was a tennis tournament that took place on the outdoor grass courts at the Germantown Cricket Club in Philadelphia, Pennsylvania, United States. The women's tournament was held from August 13 until August 18 while the men's tournament ran from September 10 until September 15. It was the 43rd staging of the U.S. National Championships and the third Grand Slam tennis event of the year.

Bill Tilden defeated Bill Johnston 6–4, 6–1, 6–4

Helen Wills defeated Molla Mallory 6–2, 6–1

Bill Tilden / Brian Norton defeated Richard Norris Williams / Watson Washburn 3–6, 6–2, 6–3, 5–7, 6–2

Kitty McKane / Phyllis Howkins Covell defeated Hazel Hotchkiss Wightman / Eleanor Goss 2–6, 6–2, 6–1

Molla Mallory / Bill Tilden defeated Kitty McKane / John Hawkes 6–3, 2–6, 10–8

• Official US Open website