J13 may refer to:
Roads County Route J13 (California) Johor State Route J13, in Malaysia
Vehicles GNR Class J13, a British steam locomotive class , a Visby-class destroyer of the Swedish Navy Shenyang J-13, a cancelled Chinese light fighter aircraft
Other uses Bacterial pneumonia Pentagonal bipyramid, a Johnson solid (J13) J13, a Nissan J engine July 13th, 2024 - the date US presidential candidate Donald Trump was shot in Butler, PA