Runa Imai (?? ?, Imai Runa, born August 15, 2000) is a Japanese swimmer.
She qualified for the 2016 Summer Olympics in Rio de Janeiro in the 200 meter individual medley.
She swam the 11th best time in the heats and qualified for the semifinals, where she was eliminated with a 15th-place finish.Imai took up swimming aged three following her elder brother Hikaru, who is also a competitive swimmer.