Gy

GY, Gy, or gy may refer to:

Units of measurement

 * Gray (unit) (Gy), SI unit of absorbed radiation
 * Giga-year, 1,000,000,000 years (non-SI)
 * Galactic year, the time it takes for the Solar System to orbit the Galactic Center

People

 * Pierre Gy (1924–2015), French chemist and statistician
 * Garin de Gy, 14th century Catholic Master of the Order of Preachers

Places

 * Gy, Switzerland, a village in the Geneva canton
 * Guyana (ISO country code: GY)
 * .gy, the country code top level domain (ccTLD) for Guyana
 * GY postcode area for Guernsey, Alderney and Sark
 * Gy, Haute-Saône, a commune in the Haute-Saône département of France
 * Great Yarmouth, United Kingdom
 * Grimsby, United Kingdom

Transport

 * GY, a Mazda automotive piston engine
 * Gabon Airlines (IATA code: GY)
 * Tri-MG Intra Asia Airlines's IATA code

Other uses

 * Hungarian gy, an alphabetic digraph
 * gy, a digraph in the Tibetan pinyin transliteration system
 * GenCorp (GY NYSE symbol)
 * Green Youth (disambiguation), one of two Green party youth wings
 * Grapevine yellows, a plant disease
 * Gy, the on-line charging interface in the GPRS core network