3420 may refer to:
A.D. 3420, a year in the 4th millennium CE 3420 BC, a year in the 4th millennium BCE 3420, a number in the 3000 (number) range
Other uses 3420 Standish, an asteroid in the Asteroid Belt, the 3420th asteroid registered IBM 3420, a 9-track open reel tape drive unit Hawaii Route 3420, a state highway Texas Farm to Market Road 3420, a state highway
See also