O
| Name | Lifetime | Genre | Notable works |
|---|---|---|---|
| Sheldon Oberman | 1949–2004 | children's literature | The Shaman's Nephew |
| Theodore Odrach | 1912–1964 | novelist | Wave of Terror |
| Alix Ohlin | novelist, short stories | Inside, Signs and Wonders | |
| Bryan Lee O'Malley | b. 1979 | graphic novelist | Scott Pilgrim |
| Heather O'Neill | novelist | Lullabies for Little Criminals | |
| Michael Ondaatje | b. 1943 | novelist, poet | The English Patient, In the Skin of a Lion, Anil's Ghost |
| Christopher Ondaatje | b. 1933 | writer and publisher | The Prime Ministers of Canada, 1867–1967, The Man-eater of Punanai — a Journey of Discovery to the Jungles of Old Ceylon, Sindh Revisited: A Journey in the Footsteps of Captain Sir Richard Francis Burton |
| Kenneth Oppel | b. 1967 | children's literature | Airborn Series, Silverwing saga |
| Stephen Osborne | b. 1947 | journalist | Ice & Fire: Dispatches from the New World |
| Martha Ostenso | 1900–1963 | novelist, screenwriter | Wild Geese |
Read more about this topic: List Of Canadian Writers