Casey O'Brien (born August 27, 2001) is an American college ice hockey player for Wisconsin of the National Collegiate Athletic Association (NCAA).

[1][8] During the 2023–24 season, in her senior year, she recorded 23 goals and 50 assists in 41 games, and helped the Badgers finish as runner-ups in the 2024 NCAA division I tournament.

[16] On October 5, 2024, O'Brien scored one goal and two assists in a game against Boston College to become the seventh player in program history to surpass 200 career points.

[19][20] O'Brien represented the United States at the 2018 IIHF World Women's U18 Championship where she recorded three goals and two assists in five games and won a gold medal.

During the semifinals against Canada, she scored the game-winning shootout goal to help the United States advance to the gold medal game.

[21] She again represented the United States at the 2019 IIHF World Women's U18 Championship, where she recorded one goal and two assists in five games and won a silver medal.