Oglesby
- County:
- LaSalle County
- County Seat:
- No
- Area (mi²):
- 4.992
- State:
- Illinois
Oglesby is a city located in LaSalle County, Illinois. Oglesby has a 2026 population of 3,626. Oglesby is currently declining at a rate of -0.19% annually and its population has decreased by -1.79% since the most recent census, which recorded a population of 3,692 in 2020.