DEC, dec or Dec may refer to:

• December - a month of the year in the Gregorian Calendar
• Digital Equipment Corporation - a computer and technology company, now part of HP
• Declination - a term from astronomy
• Diethylcarbamazine - a drug commonly used to treat infections by filarial parasites
• Disasters Emergency Committee -- a group of charities in the United Kingdom who coordinate disaster relief efforts
• Oratorical Declamation - an event in competitive debate
• Diplome d’Études Collegiales - a college studies diploma issued in Quebec
• DEC - ICAO airport code of Decatur, Illinois, US
• Declan Donnelly - a United Kingdom television presenter

DEC | DEC