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| Name | Nationality | Century | Main area/s explored |
|---|---|---|---|
| Sebastián de Ocampo | Spanish | early 16th | Caribbean, Gulf of Mexico |
| Odoric of Pordenone | Italian | early 14th | Persia, India and China |
| Peter Skene Ogden | Canadian | early 19th | Snake River country, western United States |
| Juan de Oñate | Spanish | 16th | American Southwest |
| Francisco de Orellana | Spanish | 16th | South America, Amazon River |
| John Oxley | British | early 19th | Australia |
Read more about this topic: List Of Explorers