CTR may refer to: Engineering, science and technology Counter mode (CTR mode), a cryptographic mode of operation for block ciphers X-ray crystal truncation rod, a technique to measure properties of crystal surfaces Current transfer ratio, in an opto-isolator device Content Threat Removal, a cyber security technology that defeats content threats Government Cooperative Threat Reduction, an initiative to secure and dismantle weapons of mass destruction in former Soviet Union states Currency transaction report, a report about transactions that the Bank Secrecy Act requires U.S. financial institutions to file with the Internal Revenue Service Media, arts and entertainment Contemporary Theatre Review, a British academic journal of performing arts Crash Team Racing, Naughty Dog's 1999 video game for the Sony PlayStation Crash Team Racing Nitro-Fueled, its 2019 remake Medicine Cardiac resynchronization therapy Cardio-thoracic ratio, a measure of the size of heart Carpal tunnel release, surgery for treating carpal tunnel syndrome Clinical trials registry, an official catalog for studies about health interventions, such as drugs Organizations Center for Transportation Research UT Austin, a research center at the University of Texas at Austin, US Center for Turbulence Research, a research institute at Stanford University, US Correct the Record, an American political action committee which supported Hillary Clinton's 2016 presidential campaign Computing-Tabulating-Recording Company, a company that was renamed IBM in 1924 Transport Aerolíneas Centauro (ICAO airline designator), an airline in Mexico Cattle Creek Airport, Australia (IATA code CTR) Controlled traffic region, a controlled airspace zone, typically around airports Carlton Trail Railway, a Saskatchewan, US shortline railway Chester railway station (station code), England Automobile models Honda Civic Type R, a car manufactured by Honda Ruf CTR, a car by Ruf Automobile of Germany Other uses Click-through rate, a measure of the success of an online advertising campaign "Choose the right", a common Latter Day Saint saying, often found on a CTR ring Close target reconnaissance, a military term for scouting in extremely close proximity to the target Competitive trail riding, an equestrian sport Costa Rica, ITU country code