P4 may refer to:

Computing

  • Intel Pentium 4, a processor series shipped from 2000 to 2008
  • The P4 power connector, introduced in the ATX12V 1.0 standard to power these and later CPUs
  • The i486DX (P4) model of the Intel 80486 microprocessor, introduced in 1989
  • P4 (programming language), for controlling network data forwarding
  • P4, the Perforce software command line client

Media

  • P4 Radio Hele Norge (PFI), a Norwegian radio company
  • Kanal 24 (Kanal 4), which acquired the Norwegian P4 channel from PFI
  • Sveriges Radio P4, a Swedish radio channel
  • Persona 4, a 2008 video game
  • Periphery IV: Hail Stan, a 2019 album by American progressive metal band Periphery
  • PartyNextDoor 4, a 2024 album by Canadian singer PartyNextDoor
  • Psychonaut 4, a Georgian black metal band

Military

  • Skaraborg Regiment (armoured), a Swedish army unit, designated P 4
  • Peugeot P4, a French military vehicle

Science

  • P4 laboratory, a biosafety level 4 facility
  • Tetraphosphorus (P<sub>4</sub>), an allotrope of phosphorus
  • Group p4, the plane symmetry group wallpaper group p4
  • Progesterone (Pregn-4-ene-3,20-dione), a steroid hormone
  • Kerberos, the fourth moon of Pluto
  • Perfect fourth, a musical interval
  • Enterobacteria phage P4
  • P4, an EEG electrode site according to the 10-20 system
  • P4 cell, a stage in the Caenorhabditis elegans embryonic development
  • P4-metric, in statistics, a performance metric
  • P4, three-dimensional space group number 75
  • P, three-dimensional space group number 81

Roads

  • P4 road (Latvia)
  • P04 road (Ukraine)

Other uses

  • Papyrus 4, a New Testament manuscript
  • Trans-Pacific Strategic Economic Partnership, or P4, a free trade agreement between Brunei, Chile, New Zealand, and Singapore
  • Prussian P 4, a German steam locomotive
  • Protofour, or P4, a set of standards for model railways

See also

  • 4P (disambiguation)
  • Phosphate, molecular formula <!--PO4 redirects to Phosphate; easily mistaken for P04, which redirects to here-->
  • Play (telecommunications) P4, a Polish cellular telecommunications provider