Ottawa, Illinois

Ottawa population, 2020 to 2024

Ottawa lost 46 residents from July 2020 to July 2024, a change of -0.2%. In the latest year it moved by +34. Among 330 Illinois places of 5,000 or more, that growth ranks 126th; the median place changed by -0.9%. The median place of 5,000+ in Illinois has 14,760 people, so Ottawa is 1.3 times that size.

Ottawa covers 14.90 square miles of land and 0.63 of water, for 1,260 people per square mile of land. The median Illinois place of 5,000+ has 2,177, so Ottawa is less dense than the typical town.

What county Ottawa is in

All of Ottawa's residents live in LaSalle County, which had 108,390 residents in 2024. Ottawa holds 17.3% of the county's population. The shaded shape is on the map above; dots mark the eight nearest places.

ZIP codes in Ottawa

1 ZIP Code Tabulation Area (ZCTA) overlaps Ottawa by at least 10% of the ZCTA's or the city's land: 61350. ZCTAs are Census approximations of USPS ZIP code delivery areas. The list comes from the 2020 ZCTA to place relationship file, so a city that annexed land after 2020 may reach into ZIP codes not listed here.

Where Ottawa is

The Census internal point of Ottawa is at 41.354000, -88.823400. Springfield, the capital, is 117.0 miles SSW in a straight line. The nearest larger place is Yorkville, IL (25,986 people), 29.5 miles away. The nearest city of 100,000 or more is Joliet, IL, 36.7 miles away.

Daylight in Ottawa

At 41.35° N, Ottawa gets about 15 h 10 min of daylight around the June solstice and 9 h 11 min around the December solstice, a swing of 5 h 59 min. Figures are sunrise to sunset from the SunCalc model for June 21 and December 21, 2026.

Places near Ottawa

The eight nearest incorporated places of 1,000+ in Illinois, measured between internal points. The closest is Marseilles, 8.9 miles away, with 4,779 people.