National Park Service officials say the tour bus had a dozen people onboard when the crash occurred around 2 p.m. Thursday.
Chief Ranger Bill Wright says one person was flown to Flagstaff Medical Center with serious injuries. Hospital spokeswoman Starla Collins says the hospital received one other person from the crash whose condition is unknown.
Seven others were transported by ambulance for medical treatment.
Wright says the sedan and the tour bus apparently collided head-on on the road between Grand Canyon Village and the park's east entrance, and one vehicle ricocheted into the minivan. Two parked vehicles also were damaged.
The cause of the crash is under investigation.