Yu Koshikawa (越川 優, Koshikawa Yū, born June 30, 1984) is a Japanese volleyball player who plays for Voreas Hokkaido in V.League Division 2. In July 2009, Suntory Sunbirds announced that Koshikawa would move to Pallavolo Padova next season. In July 2012, Suntory Sunbirds announced Koshikawa would join the club in the next season.