- Keighley 1885-
- Kendal 1832-1918
- Kensington 1983-1997
- Kensington North 1885-1974
- Kensington South 1885-1974
- Kensington and Chelsea 1997-
- Kensington and Chelsea Chelsea 1974-1983
- Kensington and Chelsea Kensington 1974-1983
- Kent 1660-1832
- Kent Eastern 1832-1885
- Kent Mid 1868-1885
- Kent Mid 1983-1997
- Kent Western 1832-1885
- Kerry 1832-1885
- Kerry East 1885-1922
- Kerry North 1885-1922
- Kerry South 1885-1922
- Kerry West 1885-1922
- Kettering 1918-
- Kidderminster 1832-1983
- Kildare 1802-1885
- Kildare North 1885-1922
- Kildare South 1885-1922
- Kilkenny 1801-1918
- Kilkenny 1832-1885
- Kilkenny North 1885-1922
- Kilkenny South 1885-1922
- Kilmarnock 1918-1983
- Kilmarnock District of Burghs 1832-1918
- Kilmarnock and Loudoun 1983-
- Kincardine and Deeside 1983-1997
- Kincardine and Western 1918-1950
- Kincardineshire 1708-1918
- King's County 1918-1922
- King's County 1802-1885
- King's County Birr 1885-1918
- King's County Tullamore 1885-1918
- King's Lynn 1660-1974
- Kingston 1885-1918
- Kingston and Surbiton 1997-
- Kingston upon Hull 1660-1885
- Kingston upon Hull Central 1974-1983
- Kingston upon Hull Central 1885-1955
- Kingston upon Hull East 1885-
- Kingston upon Hull Haltemprice 1950-1955
- Kingston upon Hull North 1950-1974
- Kingston upon Hull North 1983-
- Kingston upon Hull North West 1918-1950
- Kingston upon Hull South West 1918-1950
- Kingston upon Hull West 1955-1997
- Kingston upon Hull West 1885-1918
- Kingston upon Hull West and Hessle 1997-
- Kingston upon Thames 1918-1997
- Kingston upon Thames Surbiton 1974-1983
- Kingswinford 1885-1950
- Kingswood 1974-
- Kinross and West Perthshire 1950-1983
- Kinross and Western 1918-1950
- Kinsale 1802-1885
- Kirkcaldy 1974-2005
- Kirkcaldy District of Burghs 1832-1974
- Kirkcaldy and Cowdenbeath 2005-
- Kirkcudbrightshire 1708-1918
- Knaresborough 1660-1885
- Knowsley North 1983-1997
- Knowsley North and Sefton East 1997-
- Knowsley South 1983-
- Knutsford 1885-1983
2,145 constituencies in total