Seneca, Illinois

Seneca, Illinois
Business district in Seneca
Location of Seneca in Grundy County, Illinois.
Location of Illinois in the United States
Coordinates: 41°18′40″N 88°36′35″W / 41.31111°N 88.60972°W / 41.31111; -88.60972
CountryUnited States
StateIllinois
CountiesLaSalle, Grundy
TownshipsManlius, Brookfield, Erienna, Norman
Government
  MayorJeff Olson
Area
  Total
6.58 sq mi (17.03 km2)
  Land6.21 sq mi (16.08 km2)
  Water0.37 sq mi (0.95 km2)
Elevation
614 ft (187 m)
Population
 (2020)
  Total
2,353
  Density378.97/sq mi (146.31/km2)
Time zoneUTC-6 (CST)
  Summer (DST)UTC-5 (CDT)
ZIP Code(s)
61360
Area code815
FIPS code17-68640
GNIS feature ID2399784
Wikimedia CommonsSeneca, Illinois
Websitesenecail.org

Seneca is a village in LaSalle and Grundy counties in the U.S. state of Illinois. The population was 2,353 at the 2020 census, down from 2,371 at the 2010 census.

The LaSalle County portion of Seneca is part of the Ottawa, IL Micropolitan Statistical Area, while the small portion that lies in Grundy County is part of the Chicago metropolitan area.