ACR may refer to:

Medicine

• Albumin/creatinine ratio in urine
• ACR score for rheumatoid arthritis
• ACR gene, encoding the enzyme acrosin
• American College of Radiology
• American College of Rheumatology

Places

• Accrington railway station, UK, National Rail code
• Araracuara Airport, Colombia, IATA code

Science and technology

• Absolute Category Rating, a subjective quality test method
• Acumulador de Carga Rápida, a battery electric tram system
• Advanced CANDU reactor, a nuclear reactor
• Advanced Communications Riser, a PC slot format
• Advanced Contrast Ratio or Dynamic Contrast in an LCD display
• Copper tubing for air conditioning and refrigeration
• Antarctic Cold Reversal, climatic cooling about 14,500 years ago
• Anti Cam-Out Recess, an improved Philips screwdriver
• Attenuation-to-crosstalk ratio of communication links
• Automatic content recognition of video
• Adobe Camera Raw, a raw image file converter

Military and weapons

• Adaptive Combat Rifle
• Advanced Combat Rifle, a US Army program
• Armored cavalry regiment of the US army or national guard
• AČR, Army of the Czech Republic (Armáda České republiky)
• Steyr ACR, an Austrian assault rifle
• A US Navy hull classification symbol: Armored cruiser (ACR)

Other uses

• A Certain Ratio, a British post-punk band
• Accelerated chart ratio, affects streaming totals in the Official Charts Company's singles chart
• Achi language, a Mayan language of Guatemala
• Americas Cardroom, online poker site
• Dodge Viper ACR, a car