List of Proper Nouns, Cities: o

1. Oakland, California
2. Oakville
3. Oaxaca de Juárez
4. Oberhausen
5. Obihiro
6. Obninsk
7. Oceanside, California
8. Odawara
9. Odense
10. Odessa
11. Odintsovo
12. Offenbach am Main
13. Ogbomosho
14. Okara
15. Okayama
16. Okazaki
17. Okinawa
18. Oklahoma City, Oklahoma
19. Oktyabrsky
20. Oldenburg
21. Oldham
22. Olinda
23. Olmaliq
24. Olomouc
25. Olongapo City
26. Olsztyn
27. Omaha, Nebraska
28. Omdurman
29. Omiya[disambiguation needed]
30. Omsk
31. Ondal
32. Ongole
33. Onitsha
34. Ontario, California
35. Opole
36. Or Yehuda
37. Oradea
38. Oran
39. Orange, California
40. Ordos City
41. Ordu
42. Orekhovo-Zuyevo
43. Orenburg
44. Orizaba
45. Orlando, Florida
46. Orléans
47. Ormoc City
48. Orsha
49. Orsk
50. Orumiyeh
51. Oruro
52. Oryol
53. Osaka
54. Osasco
55. Osh
56. Oshawa
57. Oshogbo
58. Osijek
59. Oslo
60. Osmaniye
61. Osnabrück
62. Osorno
63. Ostrava
64. Ota
65. Otaru
66. Otsu
67. Ottawa
68. Ouagadougou
69. Ouargla
70. Oujda
71. Oulu
72. Ourense
73. Overland Park, Kansas
74. Oviedo
75. Oxford
76. Oxnard, California
77. Oyama
78. Oyo
79. Ozamiz City