The city of Ontario was founded in 1883 by developers William Morfitt, Mary Richardson, Daniel Smith, and James Virtue. The founding was in anticipation of the Oregon Short Line Railroad arriving in Ontario in late 1884, which provided freight and passenger service to the community. Shortly thereafter, cattle began arriving from many Eastern Oregon ranches, turning Ontario into one of the largest stockyards in the West. It was incorporated by the Oregon Legislative Assembly in 1899.
Ontario continued to grow in the early 1900s with the opening of Holy Rosary Hospital in 1912 and the first City Hall in 1913. In the period between World War I and II, Ontario erected a fire department, a police department, and a series of community parks. The Heinz Frozen Food Company (formerly Ore-Ida), one of Ontario’s largest employers, produces over 600 million pounds of potato products each year.
Ontario maintains a variety of attractions including: