A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
  1. Ochil 1997-2005
  2. Ochil and South Perthshire 2005-
  3. Ogmore 1918-
  4. Okehampton 1660-1832
  5. Old Bexley and Sidcup 1983-
  6. Old Sarum 1660-1832
  7. Oldbury and Halesowen 1950-1974
  8. Oldham 1832-1950
  9. Oldham Central and Royton 1983-1997
  10. Oldham East 1950-1997
  11. Oldham East and Saddleworth 1997-
  12. Oldham West 1950-1997
  13. Oldham West and Royton 1997-
  14. Orford 1660-1832
  15. Orkney and Shetland 1708-
  16. Ormskirk 1885-1983
  17. Orpington 1918-1974
  18. Orpington 1983-
  19. Osgoldcross 1885-1918
  20. Oswestry 1885-1983
  21. Otley 1885-1918
  22. Oxford 1660-1983
  23. Oxford East 1983-
  24. Oxford University 1660-1950
  25. Oxford West and Abingdon 1983-
  26. Oxfordshire 1660-1885
  27. Oxon Mid 1974-1983

2,145 constituencies in total