Mitsuru Maruoka (; born 6 January 1996) is a Japanese professional footballer who plays as a midfielder for Kansai Soccer League club .
Maruoka joined Borussia Dortmund in January 2014 on a one and a half year loan from Cerezo Osaka. He made his professional debut in the 3. Liga with the club's reserve team on 25 January 2014 against SpVgg Unterhaching.
Maruoka joined newcomer K League 2 club Gimpo FC in december 2021 after a season in BG Pathum United.
Mitsuru's brother, Satoru plays for ReinMeer Aomori in Japan Football League.