| Katella High School | |
| Motto: | "We are Katella, Embracing, Evolving, Empowering for a limitless tomorrow” |
| Established: | 1966 |
| Type: | Public |
| Principal: | Chuck Hernandez |
| Streetaddress: | 2200 E. Wagner Ave |
| City: | Anaheim |
| State: | California |
| Zipcode: | 92806 |
| Country: | United States |
| Coordinates: | 33.8236°N -117.8851°W |
| Enrollment: | 2,587 (2022-2023)[1] |
| Staff: | 110.37 (FTE) |
| Ratio: | 23.44 |
| Colors: | Scarlet, White, and Black |
| Conference: | CIF Southern Section Golden West League |
| Nickname: | Knights |
Katella High School is a public high school in Anaheim, California, located in the Southeast Anaheim region of the city and is part of the Anaheim Union High School District. It serves 2,700 students in grades nine through twelve. The school's mascot is the Knights.