Investigators responded at about 7:35 p.m. to Lewis Avenue north of Beach Road.
Witnesses told police a Mini Cooper driven by a 52-year-old Waukegan man was seen driving erratically going northbound on Lewis Avenue.
Police said the driver crossed into the southbound lanes and collided head-on with a Buick SUV and then a GMC SUV.
The driver of the Mini Cooper was transported to an area hospital, where he was in critical condition, the sheriff's office said.
The 34-year-old Buick driver, along with three child passengers, and a 48-year-old Zion woman driving the SUV were all transported to the hospital with non-life-threatening injuries.
The Lake County Sheriff's Office Technical Crash Investigation Team is investigating the crash.