- Radcliffe-cum-Farnworth 1885-1918
- Radnor District of Boroughs 1832-1885
- Radnorshire 1660-1918
- Ramsey 1885-1918
- Ravensbourne 1983-1997
- Rayleigh 1997-
- Reading 1660-1950
- Reading 1955-1974
- Reading East 1983-
- Reading North 1974-1983
- Reading North 1950-1955
- Reading South 1950-1955
- Reading South 1974-1983
- Reading West 1983-
- Redbridge Ilford North 1974-1983
- Redbridge Ilford South 1974-1983
- Redbridge Wanstead and Woodford 1974-1983
- Redcar 1983-
- Redditch 1997-
- Regent's Park and Kensington North 1997-
- Reigate 1983-
- Reigate 1885-1974
- Reigate 1660-1867
- Reigate and Banstead 1974-1983
- Renfrew West and Inverclyde 1983-1997
- Renfrewshire 1708-1885
- Renfrewshire East 2005-
- Renfrewshire East 1950-1983
- Renfrewshire Eastern 1885-1950
- Renfrewshire West 1950-1983
- Renfrewshire Western 1885-1950
- Rhondda 1885-1918
- Rhondda 1974-
- Rhondda East 1918-1974
- Rhondda West 1918-1974
- Ribble South 1997-
- Ribble Valley 1983-
- Richmond 1918-1974
- Richmond 1660-
- Richmond Park 1997-
- Richmond Upon Thames Richmond 1974-1983
- Richmond and Barnes 1983-1997
- Ripon 1660-1983
- Rochdale 1832-
- Rochester 1660-1918
- Rochester Chatham 1918-1950
- Rochester Gillingham 1918-1950
- Rochester and Chatham 1950-1983
- Rochford 1983-1997
- Rochford and Southend East 1997-
- Romford 1885-
- Romsey 1997-
- Romsey and Waterside 1983-1997
- Roscommon 1802-1885
- Roscommon North 1885-1922
- Roscommon South 1885-1922
- Ross 1885-1918
- Ross Shire 1708-1832
- Ross and Cromarty 1832-1983
- Ross and Cromarty and Skye 1983-1997
- Ross, Skye and Inverness West 1997-2005
- Ross, Skye and Lochaber 2005-
- Rossendale 1885-1983
- Rossendale and Darwen 1983-
- Rother Valley 1918-
- Rotherham 1885-
- Rothwell 1918-1950
- Rowley Regis and Tipton 1950-1974
- Roxburgh Selkirk and Peebles 1974-1983
- Roxburgh and Berwickshire 1983-2005
- Roxburghshire 1708-1918
- Roxburghshire and Selkirkshire 1918-1974
- Roxburghshire, Selkirkshire and Peeblesshire 1955-1974
- Royal Tunbridge Wells 1974-1983
- Royton 1918-1950
- Rugby 1885-1983
- Rugby and Kenilworth 1983-
- Ruislip Northwood 1983-
- Ruislip Northwood 1950-1974
- Runcorn 1950-1983
- Runnymede and Weybridge 1997-
- Rushcliffe 1885-
- Rutherglen 1918-1983
- Rutherglen and Hamilton West 2005-
- Rutland and Melton 1983-
- Rutland and Stamford 1918-1983
- Rutlandshire 1660-1918
- Rye 1660-1983
- Ryedale 1983-
2,145 constituencies in total