1. A
  2. B
  3. C
  4. D
  5. E
  6. F
  7. G
  8. H
  9. I
  10. J
  11. K
  12. L
  13. M
  14. N
  15. O
  16. P
  17. Q
  18. R
  19. S
  20. T
  21. U
  22. V
  23. W
  24. X
  25. Y
  26. Z
  1. Terrie O'Brian
  2. Claire O'Brien
  3. Kiera O'Brien
  4. Kiera O'Brien
  5. Sean O'Brien
  6. Nicola O'Byrne
  7. Jonathan O'Callaghan
  8. Joanne O'Connell
  9. Des O'Connor
  10. Bridget O'Donnell
  11. Kim O'donnell
  12. Chris O'Dowd
  13. Sheila O'Flanagan
  14. Andrew O'Hagan
  15. Mo O'Hara
  16. Kate O'Hearn
  17. Owen O'Kane
  18. A. O'kif
  19. Amanda O'Neill
  20. Martin O'Neill
  21. Bill O'Reilly
  22. P J O'Rourke
  23. Ellie O'Ryan
  24. Ellie O'Shea
  25. Feargus O'Sullivan
  26. Kate O'Sullivan
  27. Kate O'Sullivan
  28. Ronnie O'Sullivan
  29. Peter O'Toole
  30. Nicky O’Byrne
  31. Katherine Tiernan O’Connor
  32. Dermot O’Leary
  33. Olusegun Obasanjo
  34. Martine Oborne
  35. Jenny Offill
  36. Jenny Offill
  37. Sara Ogilvie
  38. Sara Ogilvie
  39. Ella Okstad
  40. Hans Olav Lahlum
  41. Jenny Oldfield
  42. Matt Oldfield
  43. Molly Oldfield
  44. Andrew Oldham
  45. Abi Oliver
  46. Mark Oliver
  47. Ramon Olivera
  48. Edith Olivier
  49. Sergio Olivotti
  50. Peter Olney
  51. David Olusoga
  52. Michael Ondaatje
  53. Yoko Ono
  54. Hiawyn Oram
  55. Baroness Orczy
  56. Miguel Ordonez
  57. Jade Orlando
  58. David Orme
  59. David and Helen Orme
  60. Cheryl Orsini
  61. Julio Ortega
  62. Davide Ortu
  63. George Orwell
  64. Jack Osbourne
  65. Kelsey Oseid
  66. Alice Oseman
  67. Richard Osmond
  68. Frank Ostaseski
  69. Matt Ottley
  70. Wil Overton
  71. Amanda Owen
  72. Lisa Owens
  73. Chris Oxlade
  74. Chris Oxlade
  75. Paul Oyer
  76. Helen Oyeyemi