Arp

Arp may refer to:

* Arp number, a numbering system for galaxies
* Arp, Texas
* Arpeggio, a broken chord in which notes are played or sung in succession rather than simultaneously
* Arpeggiator, a feature found on sound synthesizers and virtual musical instruments

Arp may refer to the following people:
* Jean Arp (1886–1966), German-French artist.
* Sophie Taeuber-Arp (1889-1943), artist
* Halton Arp (born 1927), American astronomer

ARP may refer to the following organizations:
* ARP (laboratory), a software development group for digital humanities
* Anti Revolutionaire Partij, the first Dutch political party
* ARP Instruments, Inc., an early analog synthesizer manufacturer founded by Alan Robert Pearlman
* Associate Reformed Presbyterian Church
* American Recording Productions, producers of Armenian and Middle Eastern traditional music (World Music label)

ARP may also stand for:
* Arp2/3 complex, a protein in biochemistry
* Address Resolution Protocol, a computer networking protocol.
* Active Rollover Protection.
* Aerospace Recommended Practice, guidelines for certification in the aviation industry by the Society of Automotive Engineers.
* Air Raid Precautions, in particular in the United Kingdom during World War II.
* Airport Reference Point, the approximate geometric center of all usable runways
* Arapaho language, a language spoken by native Americans.
* Area redevelopment plan, an urban planning tool provided in the Alberta Municipal Government Act.
* ARP (band), a band consisting of members Mark Rae and Rhys Adams
* ARP spoofing, a networking attack on Address Resolution Protocol
* Autoradiopuhelin (Car Radio Phone), in Finland, the first commercially operated public mobile phone network.
* Axel Rudi Pell, German guitarist