• Calcium magnesium acetate, an inorganic compound
• Calculated Match Average, a figure derived for ever rider in the sport of motorcycle speedway
• California Maritime Academy, a maritime college in Vallejo, California, USA
• Camden Military Academy, a boarding school in Camden, South Carolina, USA
• Canadian Malayalee Association
• Canadian Medical Association, a professional association of physicians in Canada
• Canadian Motorcycle Association
• Cash Management Account
• Catchment Management Authority, an land management unit in Victoria, Australia
• Census Metropolitan Area (of Canada)
• Central Mountain Air, an airline based in Smithers, British Columbia, Canada
• Centre for Microcomputer Applications, a manufacturer and distributor of products for science and technology education in The Netherlands
• Certified Management Accountant, an accountant who has met certain qualifications
• Certified Market Analyst, a financial analyst who has met certain qualifications set by the American Academy of Financial Management
• Certified medical assistant
• Chamber Music America
• Chennai Metropolitan Area, the metropolitan area around Chennai, India
• Chess'n Math Association
• Chest Medicine Associates
• Chinese martial arts
• Chinese Meteorological Association
• Chinese Military Academy, the military academy of the Republic of China, located in Fengshan, Kaohsiung County, Taiwan
• Chinese Musicians' Association
• Chocolate Manufacturers Association
• Christian Management Association
• Christian and Missionary Alliance
• Christian Motorcyclists Association
• Cleveland Museum of Art
• Chromosomal microarray analysis
• College of Marine Arts
• College Media Advisers
• Common Monetary Area
• Community College Journalism Association
• Community Media Association
• Compagnie des messageries aériennes, a French airline
• Comparative Market Analysis
• Complex metallic alloys
• Computer Misuse Act 1990
• Concert Multithreaded Architecture, a computer threading package from Digital Equipment Corporation
• Constitutional Monarchy Association
• Coordinated malware attack
• Country Music Association
• Country Music Awards
• Critical Medical Anthropology
• Crystal methamphetamine
• Crystal Meth Anonymous
• Comma (punctuation), as used in coded military communication (e.g., WWII)
• Cylindrical Mirror Analyzer, a tool for studying electron energies.
• Content-Managed Area, Software managed documents and forkflows.

CMa may stand for:

• Canis Major (constellation), standard astronomical abbreviation