- Paddington North 1885-1974
- Paddington South 1885-1974
- Paisley 1832-1983
- Paisley North 1983-2005
- Paisley South 1983-2005
- Paisley and Renfrewshire North 2005-
- Paisley and Renfrewshire South 2005-
- Partick 1885-1918
- Peckham 1983-1997
- Peebles and Southern 1918-1950
- Peeblesshire 1832-1868
- Peeblesshire and Selkirkshire 1868-1918
- Pembroke 1974-1997
- Pembroke District of Boroughs 1832-1885
- Pembroke and Haverfordwest District of Boroughs 1885-1918
- Pembrokeshire 1832-1974
- Pendle 1983-
- Penistone 1918-1983
- Penrith 1885-1918
- Penrith and Cockermouth 1918-1950
- Penrith and The Border 1950-
- Penryn and Falmouth 1832-1950
- Perth 1997-2005
- Perth 1832-1950
- Perth and East Perthshire 1950-1983
- Perth and Kinross 1983-1997
- Perth and North Perthshire 2005-
- Perthshire 1832-1885
- Perthshire Eastern 1885-1918
- Perthshire Western 1885-1918
- Peterborough 1832-
- Petersfield 1832-1983
- Plymouth 1832-1918
- Plymouth Devonport 1918-
- Plymouth Drake 1974-1997
- Plymouth Drake 1918-1950
- Plymouth Sutton 1918-
- Pontefract 1832-1974
- Pontefract and Castleford 1974-
- Pontypool 1918-1983
- Pontypridd 1918-
- Poole 1950-
- Poole 1832-1885
- Poplar 1950-1974
- Poplar Bow and Bromley 1918-1950
- Poplar South Poplar 1918-1950
- Poplar and Canning Town 1997-
- Portarlington 1832-1885
- Portsmouth 1832-1918
- Portsmouth Central 1918-1950
- Portsmouth Langstone 1950-1974
- Portsmouth North 1918-1950
- Portsmouth North 1974-
- Portsmouth South 1918-
- Portsmouth West 1950-1974
- Preseli Pembrokeshire 1997-
- Preston 1983-
- Preston 1832-1950
- Preston North 1950-1983
- Preston South 1950-1983
- Prestwich 1885-1918
- Pudsey 1950-
- Pudsey 1885-1918
- Pudsey and Otley 1918-1950
- Putney 1983-
2,052 constituencies in total