The boy was hit by an eastbound 2001 Chevy Silverado at about 4:40 p.m. in the 1900 block of West Texas Street, police said.
Police spokesman Cleo Mayoral said there is an apartment complex on one side of the street there, and a shopping center on the other with businesses including a Walgreens, a FoodMaxx, a Jack-in-the-Box and other restaurants.
A traffic light controls vehicle and pedestrian traffic and there is a crosswalk at that spot, Mayoral said.
"There's a lot of pedestrian traffic going from the apartment complex to the shopping center," Mayoral said.
He said he did not know exactly how Tuesday's collision happened but said the driver of the pickup truck, a 49-year-old Fairfield man, pulled over after striking the boy and has cooperated with investigators.
The boy, who lives at the apartment complex, suffered a cut to his head and was taken by helicopter to Children's Hospital in Oakland.
He was conscious and talking to police after the accident, Mayoral said.
"Any time there's any type of head injury ... as a precaution they get airlifted to a trauma center," Mayoral said.
The boy was listed in stable condition as of late Tuesday, he said.
The collision is under investigation by the Fairfield Police Department's traffic unit. Witnesses are encouraged to call the Police Department at (707) 428-7300.
