Yui Ohashi (Japanese: 大橋 悠依, Hepburn: Ōhashi Yui, born 18 October 1995) is a Japanese swimmer, specializing in the medley events. She became the first Japanese woman to dip beneath the 2:08-barrier in the women's 200 metre individual medley event at the 2017 World Aquatics Championships, finishing with a silver-medal time and a national record of 2:07.91. Ohashi qualified to represent Japan at the 2020 Summer Olympics. She won Japan's second gold in the 2020 Summer Olympics, winning the Women's 400m individual medley. She also won the gold medal in the Women's 200m individual medley.