Ontario (disambiguation)

In the works of Harry Turtledove, Ontario may refer to;


 * Ontario, the OTL province of Canada used as a setting for Southern Victory and Worldwar and referenced in "The Disunited States of America"
 * Ontario (The Two Georges), a province of the North American Union corresponding to OTL "Manitoba".
 * Dominion of Ontario, referenced in the Atlantis (series).