ARP
ARP or Arp stands for:
- ARP Backstage Pass , an anime television series
 - Address Resolution Protocol , a network protocol
 - Aerodrome Reference Point , see airport reference point
 - Aerospace Recommended Practices , aviation standards from the Society of Automotive Engineers
 - Anti-Revolutionaire Partij , former political party of the Netherlands
 - Atlas of Peculiar Galaxies (also called Arp catalog ), an astronomical catalog of photographic images of unusual galaxies
 - Azimuth Reference Pulse , a signal for referencing the direction of a radar antenna, see Azimuth Change Pulses
 
Companies:
- ARP Group , Swiss IT service provider
 - ARP Instruments , US company
 
AR-P stands for:
- Formosa (Province) , Argentine Province ISO-3166-2 Code
 
Arp is the name of the following places in the United States:
- Arp, Arkansas , town in Pike County - no longer exists
 - Arp (Banks County, Georgia)
 - Arp (Irwin County, Georgia)
 - Arp, Tennessee , town in Lauderdale County
 - Arp, Texas , town in Smith County
 
Arp is the family name of the following people:
- Carl Arp (1867–1913), German painter
 - Christiane Arp (* 1961), German journalist
 - Erich Arp (1909–1999), German politician
 - Fiete Arp (* 2000), German soccer player
 - Halton Arp (1927-2013), American astronomer
 - Hans Arp (also Jean Arp or just Arp ; 1886–1966), German-French painter, sculptor and poet
 - Hans-Jörn Arp (* 1952), German politician
 - Jochen Arp (* around 1950), German jazz musician
 - Julius Arp (1858–1945), German businessman and entrepreneur in Brazil
 - Julius Edgar Arp (* 1919), Brazilian swimmer
 - Klaus Arp (1950–2016), German composer, conductor and music teacher
 - Philip Arp (1929–1987), German cabaret artist and actor
 - Sophie Taeuber-Arp (1889–1943), Swiss artist
 - Wilhelm Arp (1903–1941), German National Socialist writer, educational theorist and university professor
 
Ar (p) stands for:
- a hypermodified nucleoside, see nucleosides #Hypermodified nucleosides and with a modified base structure
 
arp stands for:
- Arapaho (language) (ISO-639-3 code), Algonquian language of the Arapaho