Oikawa (written: 及川) is a Japanese surname. Notable people with the surname include:
Ataru Oikawa (及川 中, born 1957), Japanese film directorAzusa Oikawa (及川 あずさ, born 1960), Japanese fencerFumihiro Oikawa (及川 史弘, born 1973), Japanese figure skater and journalistKoshirō Oikawa (及川 古志郎, 1883–1958), Imperial Japanese Navy admiralNao Oikawa (及川 奈央, born 1981), Japanese actress, television personality and AV idolOkuro Oikawa (及川 奥郎, 1896–1970), Japanese astronomerSeijin Oikawa (及川 誠人, born 1970), Japanese motorcycle racerOikawa Teruhisa (及川 煌久, born 1936), Japanese sumo wrestlerYūya Oikawa (及川 佑, born 1981), Japanese speed skaterFictional characters:
Hazuki Oikawa (及川 葉月), a character in the manga series Moyasimon: Tales of AgricultureTooru Oikawa (及川 徹), a character in the manga series Haikyuu!!Yukio Oikawa (及川 悠紀夫), a character in the anime series Digimon AdventureFish
Zacco platypus (オイカワ、追河)