555 may refer to:

Number and year

555 (number) 555, a year of the Julian calendar 555 BC, a year of the 6th century BC

Telephone number

555 (New Zealand telephone number) 555 (North American Numbering Plan)

Entertainment

555 (1988 film), a direct-to-video horror film "555", a song by Sebastian Ingrosso "555", a song performed by the band Phish and written by Mike Gordon "555", a song by Jimmy Eat World from Surviving 5:55, an album by Charlotte Gainsbourg Ainthu Ainthu Ainthu or Five Five Five or 555, an Indian film Kamen Rider 555, also called Kamen Rider Faiz, a Japanese tokusatsu television series

Others 555, a Thai-language internet slang equivalent to LOL 555 timer IC, an integrated circuit used in a variety of timer, pulse generation, and oscillator applications State Express 555, a brand of cigarette Stagecoach bus route 555, a bus route from Lancaster to Keswick in England