After being incorporated in 1958, Ontario became a heavy manufacturing center because of the Erie Railroad line, and its proximity to Mansfield.

However, its status in that regard began to decline in the late 20th century, when much of the Erie Railroad that once ran through the city was abandoned; and shifts in the manufacturing industry led to the relocation or repositioning of many factories.

The city's industry has since diversified into the service economy, including education, finance and healthcare.

The city is also a major regional retail hub serving the entire North-Central Ohio area, with a shopping population of over 150,000.

Ontario was founded by Hiram Cook, and was platted in December 1834 as a settlement in Springfield Township near Mansfield.

[7] In 1956, General Motors built a large Fisher Body stamping plant in Springfield Township and on June 25, 1958, the residents voted to incorporate Ontario into a village to bring the new General Motors plant into Ontario.

[8] In 1960, the new Ontario High School was built, complete with an indoor swimming pool, a theatre, 3 shops, and numerous high-tech classrooms and labs for college-preparatory studies.

[9] Several annexations have been made to Ontario since its incorporation and millions of dollars have been spent on public infrastructure including streets, water and sewer facilities, parks, schools, and new civic buildings for Administrative offices, Public Safety Departments and the Water Department.

[8] The city administration offices have been housed in several different locations including the "Old Library" which is now being used as a Senior Center.

It leads west from the Norfolk Southern Railway in Mansfield to what used to be the General Motors metal stamping plant in Ontario.

[16] Ontario is located on a major east-west transportation corridor that was originally known in the early 1900s as "Ohio Market Route 3."

This route was chosen in 1913 to become part of the historic Lincoln Highway which was the first road across America, connecting New York City to San Francisco.

[17][18] In 2005, the newly upgraded section of U.S. Route 30, a four-lane limited access highway between Bucyrus and Ontario open to traffic.

[20] The Richland County Transit (RCT) operates local bus service five days a week, except for Saturdays and Sundays.