4040, 40-40 or 40/40 may refer to:
The year 4040 in the 5th millennium
Computers Intel 4040, a microprocessor Commodore 4040, a model of floppy disk drive
Roads County Road 4040 (Volusia County, Florida), a historic road A4040 road, a road in Birmingham, England
Sports and games 40–40 club, a term in baseball The 40/40 Club, a sports bar chain Forty forty, a children's game
Music 40/40 (The Carpenters album) 40/40: The Best Selection (Olivia Newton-John album)
Other 4040 Purcell, an asteroid