900 may refer to:

Numbers 900 (number), a number in the 900s range 900 telephone number, an area code in North America reserved for additional charge calling

Time AD 900, a year in the first millennium of the Common Era 900 BC, a year in the first millennium Before Common Era 900s (decade) AD, a decade in the first millennium of the Common Era 900s BC (decade), a decade in the first millennium Before Common Era 900s (century) AD, a century in the first millennium of the Common Era 900s BC (century), a century in the first millennium Before Common Era 9/00, September 2000 9/00, September 1900

Places 900 Rosalinde (1918 EC), a main-belt asteroid, the 900th asteroid registered Căile Ferate Române Line 900, the 900 line operated by Căile Ferate Române, a rail line in Romania

Legislation Decree 900, Guatemalan land reform law of 1952 H.R. 900, the Puerto Rico Democracy Act, a federal bill in the United States, 2007

Military Ships with pennant number 900 , a Royal Netherlands Navy submarine support ship , a WWII U.S. Navy tank landingship

Products Astra Model 900, a semiautomatic pistol Commodore 900, a microcomputer

Vehicles Bréguet 900 Louisette, a sailplane GMT900, a General Motors full-size pickup truck GS&WR Class 900, a locomotive class MD 900, a model of helicopter from McDonnell Douglas Helicopters Saab 900, a mid-sized automobile Fiat 900T, also known as the Fiat 900e and Zastava 900, a van South Australian Railways 900 class, a locomotive class

Other uses 900MHz (33cm), a UHF band UMTS 900, a frequency band for cellular telephony 900 AM (900kHz; 333m), a radio station frequency 900 (skateboarding), a 900° spin, also found in skiing and snowboarding 900 mm gauge railways 900 Airport Express, an airport bus route in the Greater Toronto Area

See also List of highways numbered 900

1-900 (disambiguation) 900 series (disambiguation) 900s (disambiguation) C900 (disambiguation) E900 (disambiguation) P900 (disambiguation) S900 (disambiguation) V900 (disambiguation) W900 (disambiguation)