GCM may refer to:
Awards Good Conduct Medal (United States), a military award Grand Cross of the Order of Merit (Portugal) Knight Grand Cross Royal Order of Monisaraphon, post-nominal letters
Organizations GCM Resources, a British mining company Global Campaign for Microbicides Great Commission Ministries, an American Christian evangelistic organization Great Central Mines, a defunct Australian mining company
Science and technology Galois/Counter Mode, in cryptography General circulation model, or global climate model Google Cloud Messaging Greatest common measure Ground continuity monitor
Transport Claremore Regional Airport, in Oklahoma (FAA LID code) Owen Roberts International Airport, Grand Cayman, Cayman Islands (IATA code) Grand Central Madison, a commuter rail terminal
Other uses Global Compact for Migration, a proposed international treaty Grand Corps Malade (born 1977), French slam poet Gross combination mass Genesis Climber MOSPEADA, a Japanese animated TV series