Authorities say the accident happened at about 10 p.m. in the 1000 block of El Segundo Boulevard. The victim was rushed to a local hospital, where he was listed in grave condition.
Police identified the bicyclist as 60-year-old Jessie Dotson of Gardena. He was reportedly riding his bicycle to work.
Dotson's family has gathered by his hospital bedside. The grandfather of three is in a coma after suffering a life-threatening head injury.
The vehicle that struck the victim was described as a dark-colored compact vehicle and should have damage to the front windshield.
Investigators say they do not have any leads on a suspect. Anyone with information is urged to call Gardena police at (310) 217-9600.