ARPA may refer to any of the following:

  1. Short for Advanced Research Projects Agency, ARPA is a US agency first led by Dr. J.C.R. Licklider to help fund and promote research after the Soviet Union launched Sputnik in 1957. This agency helped make ARPANET and was later renamed to DARPA in 1972.

  2. Short for address and routing parameter area, .arpa is a top-level domain created for transitions from ARPANET hostnames to the newer DNS Type names in the late 1980s.

  3. The Internet domain suffix .arpa is short for Internet infrastructure TLD.

ARPANET, Computer abbreviations, IPTO, Network terms