ONT may refer to:
Ontario International Airport (IATA code ONT), in Ontario, California, United States
Ontario (Ont.), traditional abbreviation for the Canadian province of Ontario; although ON is the proper postal abbreviation
Optical Network Terminal, an interface between a company's fiber optic network and premises wiring
Ontario Northland Railway, a Canadian railroad
Ordo Novi Templi, Order of the New Templars, an occult anti-semitic society founded 1907 by Lanz von Liebenfels
Ontario Network Television, the main predecessor of the now-defunct Baton Broadcast System (Canada)
Obshchenatsional...