Onch'à Ân County is a county in South P'yà Ângan province, North Korea. It is administered as part of Namp'o Special City.
Onch'Ã Ân county is divided into 1 Ã Âp (town), 5 rodongjagu (workers' districts) and 14 ri (villages):
Onch'à Ân county is served by the P'yà Ângnam and Ryonggang lines of the Korean State Railway.