2P may refer to: Science 2P/Encke, official designation of Comet Encke 2p, an arm of Chromosome 2 (human) 2p, an atomic orbital for electrons Two-photon absorption Two-photon excitation microscopy Transportation Airphil Express, a Philippines airline, IATA code 2P LMS Class 2P 4-4-0, a British locomotive Other 2P, a 408mm artillery piece from the Soviet Union 2p, a two pence British coin 2P, rapper 2 Pistols 2P reserves, proven reserves of fossil fuels See also P2 (disambiguation)