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. Nicola O'Byrne
  8. Jonathan O'Callaghan
  9. Joanne O'Connell
  10. Des O'Connor
  11. Bridget O'Donnell
  12. Kim O'donnell
  13. Chris O'Dowd
  14. Sheila O'Flanagan
  15. Andrew O'Hagan
  16. Mo O'Hara
  17. Kate O'Hearn
  18. Owen O'Kane
  19. A. O'kif
  20. Amanda O'Neill
  21. Martin O'Neill
  22. Bill O'Reilly
  23. P J O'Rourke
  24. Ellie O'Ryan
  25. Ellie O'Shea
  26. Feargus O'Sullivan
  27. Kate O'Sullivan
  28. Kate O'Sullivan
  29. Ronnie O'Sullivan
  30. Suzanne O'Sullivan
  31. Peter O'Toole
  32. Nicky O’Byrne
  33. Katherine Tiernan O’Connor
  34. Dermot O’Leary
  35. Olusegun Obasanjo
  36. Obie Oberholzer
  37. Martine Oborne
  38. Jenny Offill
  39. Jenny Offill
  40. Sara Ogilvie
  41. Sara Ogilvie
  42. Ella Okstad
  43. Hans Olav Lahlum
  44. Jenny Oldfield
  45. Matt Oldfield
  46. Molly Oldfield
  47. Andrew Oldham
  48. Abi Oliver
  49. Mark Oliver
  50. Ramon Olivera
  51. Edith Olivier
  52. Sergio Olivotti
  53. Peter Olney
  54. Jacqueline Olson
  55. David Olusoga
  56. Michael Ondaatje
  57. Yoko Ono
  58. Hiawyn Oram
  59. Baroness Orczy
  60. Miguel Ordonez
  61. Jade Orlando
  62. David Orme
  63. David and Helen Orme
  64. Cheryl Orsini
  65. Julio Ortega
  66. Davide Ortu
  67. George Orwell
  68. Jack Osbourne
  69. Kelsey Oseid
  70. Alice Oseman
  71. Richard Osmond
  72. Frank Ostaseski
  73. Matt Ottley
  74. Wil Overton
  75. Amanda Owen
  76. Lisa Owens
  77. Chris Oxlade
  78. Chris Oxlade
  79. Paul Oyer
  80. Helen Oyeyemi