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 The Intel 486, officially named i486 and also known as 80486, is a microprocessor introduced in 1989. It is a higher-performance follow-up to the i386, Intel 386. It represents the fourth generation of binary compatible CPUs following the Inte ...

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 P4 (''pe fyra'') is a national radio channel produced by the Swedish public broadcaster Sveriges Radio. P4 was started in 1987 as a network of regional stations, but national programming was added in 1993 when P3 was relaunched as a specialist you ...

, a Swedish radio channel * ''

Persona 4 is a 2008 role-playing video game by Atlus. It is chronologically the fifth installment in the ''Persona (series), Persona'' series, itself a part of the larger ''Megami Tensei'' franchise, and was released for the PlayStation 2 in Japan in Ju ...

'', a 2008 video game * '' Periphery IV: Hail Stan'', 2019 album by American progressive metal band Periphery

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 (P₄), an allotrope of phosphorus * Group p4, the plane symmetry group wallpaper group ''p''4 *

Progesterone Progesterone (; P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the ma ...

(Pregn-4-ene-3,20-dione), a steroid hormone * Kerberos, the fourth moon of Pluto *

Perfect fourth A fourth is a interval (music), musical interval encompassing four staff positions in the music notation of Western culture, and a perfect fourth () is the fourth spanning five semitones (half steps, or half tones). For example, the ascending int ...

, 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

Roads

* P4 road (Latvia) * P04 road (Ukraine)

Other uses

Papyrus 4 Papyrus 4 (, part of ''Suppl. Gr.'' 1120) is an early List of New Testament papyri, New Testament papyrus of the Gospel of Luke in Greek language, Greek. Opinions differ as to its age. It has been dated anywhere from the late second century to th ...