N-O
| Nectar | ˈnɛktɑr | Runs E from Solis Lacus to Nectaris Fons (near Protei Regio) | From nectar, the legendary drink of the gods |
| Neda | ˈniːdə | A river of the Peloponnesus | |
| Nepenthes | niːˈpɛnθiːz | NE to SW: from junction of Thoth and Triton canals to Syrtis Major via Lacus Moeris | |
| Nereides | niːˈriːədiːz | From the nymphs called Nereids | |
| Nestus | ˈnɛstəs | A river of Thrace | |
| Neudrus | ˈnjuːdrəs | A river of India | |
| Nilokeras | naɪˈlɒkɨræs | E to W: connects Niliacus Lacus with Lunae Lacus | Means "horn of the Nile" |
| Nilosyrtis | ˌnɪloʊˈsɪrtɨs | A broad canallike feature, running N from the tip of Syrtis Major to Coloë Palus | |
| Nilus | ˈnaɪləs | From the Nile, the river of Egypt | |
| Nymphaeus | nɪmˈfiːəs | A river of Armenia | |
| Oceanus | oʊˈsiːənəs | From Oceanus, a mythical river surrounding the world and the Titan who shared its name | |
| Ochus | ˈoʊkəs | A river of Bactriana | |
| Opharus | ˈɒfərəs | A river of Sarmatia | |
| Orcus | ˈɒrkəs | NW to SE: connects Trivium Charontis to Nodus Gordii, where it turns into Eumenides canal | From Orcus, a synonym of Hades |
| Orontes | oʊˈrɒntiːz | E to SW: connects Serbonis Palus to Sabaeus Sinus | From the Orontes, a river of Syria |
| Orosines | |||
| Oxus | ˈɒksəs | NE to SW: connects the Deuteronilus and the Indus canals | From an old name for the Amu Darya, a river of Central Asia |
Read more about this topic: List Of Martian Canals