ARC may refer to:

• Airlines Reporting Corporation, an airline-owned company that provides ticket distribution, reporting, and settlement services
• Airport Regions Conference, a European organization of major airports
• Amalgamated Roadstone Corporation, a British stone quarrying company
• American Record Company (1904–1908, re-activated 1979), one of two United States record labels by this name
• American Record Corporation (1929–1938), a United States record label also known as American Record Company
• American Reprographics Company
• Amey Roadstone Construction, a former British construction company
• Aqaba Railway Corporation, a freight railway in Jordan
• A&R Channel, American cable television video on demand network based in Los Angeles
• ARC/Architectural Resources Cambridge, Inc., Cambridge, Massachusetts
• ARC Diversified, a Cookeville, Tennessee non-profit that employs the severely disabled
• ARC International, a computer processor designer, and a subsidiary of Synopsys 
• Archaeological Review from Cambridge, UK journal
• Arena Racing Company, a British racecourse owning group

Arc may refer to:

• Arc (protein), a name of product of an immediate early gene, also called Arg3.1
• Arc system, a 2-component system found in prokaryotes, used to detect celular redox poise

ARC is a lossless data compression and archival format by System Enhancement Associates (SEA). It was very popular during the early days of networked dial-up BBS. The file format and the program were both called ARC. The ARC program made obsolete the previous use of a combination of the SQ program to compress files and the LU program to create .LBR archives, by combining both compression and archiving functions into a single program. Unlike ZIP, ARC is incapable of compressing entire directory trees. The format was subject to controversy in the 1980s—an important event in debates over what would later be known as open formats.