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  1. O'Brien, Lucy
  2. O'Brien, Sean
  3. O'Byrne, Nicola
  4. O'Byrne, Nicola
  5. O'Connell, Joanne
  6. O'Connor, Bridget
  7. O'Connor, Deborah
  8. O'Connor, Elizabeth
  9. O'Donnell, Bridget
  10. O'Dowd, Chris
  11. O'Hara, Lauren
  12. O'Hara, Mo
  13. O'Hara, Natalia
  14. O'Hare, Gráinne
  15. O'Kane, Owen
  16. O'Neill, A.D.
  17. O'Neill, Amanda
  18. O'Neill, Heather Aimee
  19. O'Neill, Martin
  20. O'Reilly, Bill
  21. O'Rourke, P. J.
  22. O'Shaughnessy, Patrick
  23. O'Sullivan, Ronnie
  24. Oakley, Phil
  25. Oakley, Stu
  26. Oates, Joyce Carol
  27. Obasanjo, Olusegun
  28. Oborne, Martine
  29. Odette, Tessonja
  30. Odo
  31. Ogilvie, Sara
  32. Ojari, Daniel
  33. Olav Lahlum, Hans
  34. Oldfield, Matt & Tom
  35. Oldfield, Richard
  36. Oliver, Abi
  37. Oliver, Joshua
  38. Olivotti, Sergio
  39. Ollerton, Ollie
  40. Olley, Darcie
  41. Olsen, Chris
  42. Olson, Jessica S.
  43. Olson, Parmy
  44. Olusoga, David
  45. Olusoga, Kemi
  46. Olusoga, Yinka
  47. Ondaatje, Michael
  48. Orczy, Baroness
  49. Ord, Charlotte
  50. Orie, Rima
  51. Orlando, Jade
  52. Orsenna, Érik
  53. Ortega, Julio
  54. Orwell, George
  55. Osborne, George
  56. Oseid, Kelsey
  57. Osman, Jim
  58. Osmond, Richard
  59. Ostaseski, Frank
  60. Ounsley, Jodie
  61. Owen, Amanda
  62. Owen, Sid
  63. Owens, Lisa
  64. Oxlade, Chris
  65. Oyemakinde, Tomi
  66. Oyeyemi, Helen
  67. Ozawa, Eric
  68. O’Connor, Katherine Tiernan
  69. O’Hart, Sinéad
  70. O’Neill, Eamonn