Police said the vehicle was found on Tuesday at about 4:20 p.m. by a company that was conducting sonar scans in the area.
The body of a man was found in the driver's seat, police said. The man still had his seatbelt on.
Waukegan police said the vehicle matches information from a missing persons report from 2024.
The Lake County Coroner's Office was notified and responded to the scene.
Officials did not release any further information.