CET or cet may refer to:

• Cet, Albania
• Cet, standard astronomical abbreviation for the constellation Cetus
• Colchester Town railway station (National Rail code CET), in Colchester, England

• Comcast Entertainment Television, a Denver, Colorado TV station
• Community Educational Television, a station ownership arm of the Trinity Broadcasting Network
• Coventry Evening Telegraph, a newspaper in Coventry, England
• WCET-TV, a PBS station serving Cincinnati, Ohio

• Center for Educational Technology, in Israel, producing learning materials

• College of Engineering, Trivandrum, in Kerala, India
• College of Engineering and Technology, in Bhubaneswar, Orissa, India

• College English Test, a national English examination in People's Republic of China
• Common Entrance Test, for prospective students seeking entry into institutes of higher education in India

• Carrier Ethernet Transport, an Ethernet extension
• Center for Environmental Technology, a radio receiver designer
• Certified engineering technologist, a Canadian qualification
• Control-flow enforcement technology, a security technology by Intel
• Critical exposure temperature, a factor in determining the minimum design metal temperature
• FV180 Combat Engineer Tractor

• Caesars Entertainment Corporation, often abbreviated as "CET"
• Canadian Equestrian Team
• Carbon emissions trading
• Central England temperature, a set of monthly records dating back to the seventeenth century
• Central European Time, UTC+1:00
• Cognitive evaluation theory, a psychological theory explaining environment's effects on motivation
• Colombo Electric Tramways
• A common external tariff applied by a customs union
• Common Eligibility Test, an examination for government recruitment in India