Katherine Hui

Katherine Hui (born 29 January 2005) is an American tennis player. She became the girls' singles champion at the 2023 US Open.

Early and personal life
From San Diego, California, Hui graduated from Santa Fe Christian High School in 2023 and committed to Stanford University. Her parents, Yimei and Yan, were born in China before moving to the United States.

Juniors
Hui qualified for the prestigious junior tournament Les Petits As, in Tarbes in January 2019. At the tournament she lost to eventual champion Linda Fruhvirtova in the quarterfinal. Hui and her partner, Kayla Cross from Canada, were the runner-up in doubles.

In 2022, at the Billie Jean King Girls’ 16s and 18s National Championships, Hui reached the semi-finals. In 2023, at the Billie Jean King Girls’ 16s and 18s National Championships, Hui reached the final but was defeated in three sets by Clervie Ngounoue.

Awarded a wildcard into the Girls' singles at the 2023 US Open, Hui won the tournament by defeating Tereza Valentova in straight sets. Hui did not lose a set throughout the tournament.

Professional career
Awarded a wildcard for the qualifying competition at the 2023 US Open women's singles, Hui lost in the first round to Eugenie Bouchard.

She received a wildcard for the 2024 San Diego Open for her WTA main draw debut where she lost to seventh seed Donna Vekic.