Arg or ARG may refer to:
Places
- Arg () means "citadel" in Persian, and may refer to:
- Arg, Iran, a village in Fars Province, Iran
- Arg, Kabul, presidential palace in Kabul, Afghanistan
- Arg, South Khorasan, a village in South Khorasan Province, Iran
- Arg of Karim Khan
- Arg of Tabriz
- Arg-é Bam, an ancient citadel in Bam, Iran
- Arg-e Rayen, Kerman, Iran
- Herat Citadel, also known as Arg-e Herat
- ARG, the ISO 3166-1 alpha-3 and UNDP country code for Argentina
People
- James Argent, nicknamed "Arg"
Arts, entertainment, and media
- Alternate reality game
- American Record Guide, a classical music magazine
- Archive for Reformation History, journal
- Arg!, a mod for the 1998 video game Half-Life
Mathematics
- Argument (complex analysis), the angular component of a complex number or function
- Argument of a function, a specific input in a mathematical function
Military
- A US Navy hull classification symbol: Internal combustion engine repair ship (ARG)
- Amphibious ready group of US Navy
Organizations and enterprises
- Aerolíneas Argentinas (ICAO: ARG)
- American Research Group, US polling research firm
- Architectural Resources Group, a firm based in San Francisco, US
- Architectural Research Group, Philadelphia, US, 1932–35
- Austin Rover Group, 1980s UK carmaker
Transportation
- ARG Argentina Línea Privada, 2001–02, at other times airline LAPA (Líneas Aéreas Privadas Argentinas)
- Arisaig railway station, UK, National Rail code
- Australian Railroad Group, a former rail freight operator
Other uses
- Antigua Recreation Ground, the national stadium of Antigua and Barbuda
- Former Argentine gold and silver pesos, ISO 4217 code
- Arginine, an α-amino acid abbreviated as Arg or R
- Aragonese language, ISO 639 alpha-3 code arg