FAA officials said a single-engine Grumman AA-5 aircraft landed long at the airport and went off the end of the runway around 3:15 p.m.
No one was killed. No fire was reported.
Most of the people on board suffered back injuries. One victim was treated for a leg injury. All were airlifted to Harbor-UCLA Medical Center and Los Angeles County-USC Medical Center.
Catalina Airport sits on top of a cliff.
It's unknown whether the plane was in the process of landing or taking off at the time of the crash.