3140 may refer to:

• A.D. 3140, a year in the 4th millennium CE
• 3140 BC, a year in the 4th millennium BCE
• 3140, a number in the 3000 (number) range

Other uses

• 3140 Stellafane, an asteroid in the Asteroid Belt, the 3140th asteroid registered
• Hawaii Route 3140, a state highway
• Louisiana Highway 3140, a state highway
• Texas Farm to Market Road 3140, a state highway