J15 may refer to:
Vehicles Aircraft Junkers J 15, a German experimental aircraft Shenyang J-15, a Chinese carrier-based jet fighter
Locomotives GSR Class J15, an Irish steam locomotive LNER Class J15, an English steam locomotive class
Ships , a Sandhayak-class survey ship of the Indian Navy
Other uses Bacterial pneumonia County Route J15 (California), a County route in Tulare County, California Elongated square bipyramid, a Johnson solid (J15) J15, a Nissan J engine model