Ontario (disambiguation)

Ontario may refer to:


 * Ontario, Canada, a province, formerly known as Upper Canada and Canada West.
 * Ontario County, New York
 * Ontario County, Pennsylvania later renamed Bradford County.

Ontario may also refer to other places such as:


 * Ontario, San Bernardino, California
 * Ontario, Knox, Illinois
 * Ontario, LaGrange, Indiana
 * Ontario, Story, Iowa
 * Ontario, Jackson, Kansas
 * Ontario, Wayne, New York
 * Ontario, Richland, Ohio
 * Ontario, Malheur, Oregon
 * Ontario, Washington, Pennsylvania
 * Ontario, Charlotte, Virginia
 * Ontario, Vernon, Wisconsin