ARB, ARb or arb may refer to:
Brands and enterprises ARB, Inc., predecessor of Primoris Services Corporation American Research Bureau ARB (Azerbaijani TV channel), an Azerbaijani television network ARB 24, an Azerbaijani television news channel ARB 4x4 Accessories ARB Günəş, an Azerbaijani children's television channel Amanah Raya Berhad, a Malaysian trustee company
Computing Arb, arbitrary-precision package, part of FLINT: Fast Library for Number Theory OpenGL Architecture Review Board ARB assembly language, for GPU instructions
Government Administrative Review Board (Labor) of the US Department of Labor Air Resources Board, California Environmental Protection Agency Architects Registration Board, UK statutory body
Language Arb (gesture), hand signals used on financial trading floors Modern Standard Arabic (ISO 639-3 code)
Military Administrative Review Board, for prisoners in the Guantánamo Bay detention camps Air Rescue Boat Two US Navy hull classification symbols: Battle damage repair ship (ARB) and Base repair ship (ARb)
Science, engineering, and health care Accumulative roll bonding of metal sheets Angiotensin II receptor blocker, a blood pressure medication Anti-roll bar, automotive suspension component to improve stability during cornering, known as a 'sway bar' in US English ARB Project, for phylogenetic analysis Arbitrary unit or arb unit Royal Academies for Science and the Arts of Belgium ()
Sports ARB (martial art), a Russian martial art Australian Racing Board for horse racing
Transportation Ann Arbor station, Amtrak station in Michigan, station code Ann Arbor Municipal Airport (IATA airport code) Arbroath railway station, UK (National rail code) Arth-Rigi-Bahn, a Swiss mountain railway
Other uses ARB, Accounting Research Bulletin, documents on accounting issues revised by the Accounting Principles Board ARB (band), a Japanese rock band Breton Revolutionary Army (), an illegal organization