1921 U.S. National Championships – Women's singles

Molla Mallory defeated Mary Browne 4–6, 6–4, 6–2 in the final to win the women's singles tennis title at the 1921 U.S. National Championships. The women's event was organized for the first time at the West Side Tennis Club, Forest Hills, New York City and was held from August 15 through August 20, 1921. It was Mallory's sixth U.S. National singles title.^[1][2] In the second round of the event, Mallory defeated Suzanne Lenglen for the only time in her career. Suzanne Lenglen was making her only ever competitive appearance in the United States. She retired from the match after losing the first set, the only competitive loss after World War I of her career.

Women's singles
1921 U.S. National Championships
Champion	Molla Mallory
Runner-up	Mary Browne[1]
Score	4–6, 6–4, 6–2
Draw	64
Seeds	–

Draw

Final eight

	Quarterfinals							Semifinals							Finals
		Patricia Hitchins	8	6
		Adelaide Greene	6	2
									Patricia Hitchins	3	0
									Mary Browne	6	6
		Ann Cole	1	2
		Mary Browne	6	6
																Mary Browne	6	4	2
																Molla Mallory	4	6	6
		Helene Falk	2	1
		Molla Mallory	6	6
									Molla Mallory	8	6
									May Sutton Bundy	6	2
		May Sutton Bundy	6	6
		Helen Gilleaudeau	1	2