1. O Reef
2. Oa-to
3. Obel Island
4. Obella
5. Obella Island
6. Obioati
7. Obire
8. Obire-to
9. Oca
10. Odia
11. Odia
12. Odia Atoll
13. Odia Insel
14. Odile
15. Odjia
16. Odtia
17. Oiiko-to
18. Oja
19. Okoreppu Island
20. Oleander
21. Olive
22. Ollot
23. Ollot Island
24. Olot
25. Ombelim

26. Ombelim Channel
27. Ombelim Island
28. Ombelim Pass
29. Ombelim-Sand
30. Ombiririen-suido
31. Ombiririen-to
32. Omelek
33. Omelek Island
34. On Island
35. Onbirien To
36. Onbiririen Suido
37. Onbiririen To
38. Onemak
39. Onemak East Passage
40. Onemak Island
41. Onemak West Passage
42. Ongw
43. Onimaaku
44. Onimaari To
45. Onimak
46. Onimak Island
47. Onimaku-to
48. Onimaku-to
49. Onimitchi Island
50. Oninaen