The shooting happened hours before the start of school at about 4:45 a.m. Orange County sheriff's investigators say the deputy tried to pull the man over for a traffic violation after he drove through a gate and into the school parking lot.
The suspect crashed through a gate near the athletic field. The deputy fired at least one shot, hitting the driver and wounding him.
"I believe the suspect was outside the vehicle, but that's still under investigation," said O.C. County Sheriff's Department spokesman Jim Amormino. "As the suspect's vehicle was being towed it did appear that the driver's window was shot out, but again how that occurred, I do not have that information."
It was not clear why the deputy opened fire. The driver's name has not been released.
The O.C. District Attorney's Office is investigating the incident.