Monroe County Sheriff's Office said the crash happened shortly before 6 a.m. on Deerfield Highway, east of Bragg Road in Summerfield Township.
Officials said Jarrett E. Callahan, 18, of Deerfield, was sent to the hospital in serious condition after his 2002 Chevrolet Tahoe crossed the centerline and hit head-on a 2004 Chrysler Sebring.
The driver of the Sebring, Radley J. Wade, 25, of Tecumseh, is listed in critical condition.
His passengers, Charles E. Hopkins, 30, of Osseo, and Justin A. Smith, 19, of Lambertville, were listed stable condition.
Both drivers had been wearing their seatbelts.
Alcohol does not appear to be a factor in the crash, according to officials.
The crash remains under investigation. Anyone with information is asked to call 734-240-7493.