501 is a year in the Common Era.

501 may also refer to:

501 BC, a year in the era B.C. 501 (number)

Military Avro 501, a military seaplane 501 Squadron (disambiguation), several units 501 Organization, a fictional unit from a Japanese anime series Ghost in the Shell: Arise

Transportation List of highways numbered 501 Flight 501 (disambiguation), several flights 501 Queen, a streetcar route in Toronto Allison 501, an aircraft turboprop engine BMW 501, a luxury car produced by BMW British Rail Class 501, an electric multiple unit train type Fiat 501, a small family car produced by Fiat

Other uses 501, the name of a game of darts Section 501, a provision of the Australian Migration Act 1958 The record score in first-class cricket by Brian Lara, and also Lara's brand of clothing in honour of this event a type of Levi's jeans an HTTP status code meaning Not implemented SMTP Error - 501, an SMTP status code meaning Syntax error in parameters or arguments 501(c), a type of tax exemption for non-profit organizations in the United States Area code 501, covering part of Arkansas, U.S. Year 501: The Conquest Continues, a book by Noam Chomsky 501 Urhixidur, an asteroid SARS-CoV-2 Beta variant, variant of COVID-19 also known as 501.V2 or 501Y.V2

See also 501st (disambiguation)