The collision was reported shortly before 7:30 a.m. at the intersection of Royal Avenue and Vaquero Drive, according to the Simi Valley Police Department.
The crossing guard suffered "significant" injuries and was transported to a hospital in unknown condition, police Sgt. Steve Shorts said. The vehicle's driver, a man who was not impaired, remained at the scene, the sergeant said.
Traffic at the intersection is regulated by a stoplight, investigators said, but the color of the light at the moment of impact was unclear.
The age of the pedestrian who was pushed out of the vehicle's path was unknown, but Shorts confirmed the person was not a student.