P8, P-8, P.8, or P 8 may refer to:
In transportation or aviation
- Boeing XP-8, 1920s US prototype biplane
- Boeing P-8 Poseidon, an anti-submarine warfare and maritime patrol aircraft
- Bowin P8, Formula 5000 and Formula 2 race cars
- Former Pantanal Linhas Aéreas, Brazilian airline with IATA code P8
- Piaggio P.8, a 1928 Italian floatplane
- Prussian P 8, a German locomotive, 1906-1923
- P8, IATA code for SprintAir, a Polish airline
In technology
- FileNet P8, system development framework
- Huawei P8, phablet
- Sony Cyber-shot DSC-P8, camera
In other fields
- Heckler & Koch P8, a 9 mm pistol
- Luger P08, a 9mm pistol
- P8 abbreviation for octave interval
- P8, Political Eight, or "G7+1", see G8
- P8 Group of pension funds
- P8, a hypothetical allotrope of phosphorus
- Danish public radio station DR P8 Jazz