The map above shows Illinois and Ontario side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Illinois vs Ontario Geography
Land area
- Illinois has a land area of 55,513 square miles (143,778 km²), while Ontario has 354,342 square miles (917,741 km²).
- Ontario's land area is 6.4 times (538%) larger than Illinois'.
Total area
- Illinois: 57,913 square miles (149,995 km²) vs Ontario: 415,598 square miles (1,076,395 km²), including inland and coastal water.
- Ontario's total area is 7.2 times (618%) larger than Illinois'.
Length
- Illinois is 390 miles (628 km) long from north to south; Ontario is 1,085 miles (1,747 km).
- Ontario's north-south length is 2.8 times (178%) longer than Illinois'.
Width
- Illinois spans 283 miles (456 km) east to west; Ontario spans 1,013 miles (1,630 km).
- Ontario's east-west width is 3.6 times (258%) wider than Illinois'.
Highest point
- Illinois's highest point is Charles Mound at 1,232 feet (376 m); Ontario's is Ishpatina Ridge at 2,274 feet (693 m).
- Ishpatina Ridge is 1,042 feet higher than Charles Mound.
Lowest point
- Illinois's lowest point is Mississippi River at 292 feet; Ontario's is Hudson Bay at 0 feet.
- Ontario's lowest point is 292 feet lower.
Illinois vs Ontario Population and History
Population
- Illinois has a population of 12,710,158 (2024), while Ontario has 16,136,480 (2026).
- Ontario's population is 1.3 times (27%) larger than Illinois'.
Population density
- Illinois: 229.0 people per square mile vs Ontario: 45.5.
- Illinois' population density is 5.0 times (403%) higher than Ontario's.
Biggest city
- Illinois's biggest city is Chicago with 2,721,308 people; Ontario's is Toronto with 2,794,356.
- Chicago and Toronto have about the same population.
Largest metro area
- Illinois's largest metropolitan area is Chicago-Naperville-Elgin, IL-IN metro area (9,408,576 people) vs Ontario's Toronto CMA (6,202,225).
- Chicago-Naperville-Elgin, IL-IN metro area's population is 1.5 times (52%) larger than Toronto CMA's.
History
- Illinois: Admitted to the Union on December 3, 1818, as the 21st state.
- Ontario: Joined Confederation on July 1, 1867, as one of the four founding provinces.
- In its current form, Illinois is the older of the two by 49 years.
Illinois vs Ontario Economy
GDP
- Illinois's GDP is $1,148.1 billion (2024) vs Ontario's $873.9 billion.
- Illinois' economic output is 1.3 times (31%) larger than Ontario's.
GDP per capita
- Illinois: $90,330 per person vs Ontario: $54,132.
- Illinois' GDP per capita is 1.7 times (67%) higher than Ontario's.
Official Websites
Illinois official website · Ontario official website
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More Size Comparisons
All Illinois size comparisons · All Ontario size comparisons
Area, elevation and boundary figures come from official national statistics and US Census Bureau and Natural Earth boundary data; US state population, economic, county and tax figures come from the US Census Bureau, the Bureau of Economic Analysis and the Tax Foundation. Figures are rounded and for general reference.