| Alleman High School | |
| Streetaddress: | 1103 40th Street |
| City: | Rock Island |
| State: | Illinois |
| Zipcode: | 61201-3199 |
| Country: | USA |
| Coordinates: | 41.4996°N -90.5449°W |
| Denomination: | Catholic |
| Principal: | Jane Barrett and Mike Lootens |
| Chaplain: | Fr. Patrick Wille |
| Teaching Staff: | 28.9 |
| Ceeb: | 143-720 |
| Ratio: | 15.1 |
| Act: | 22 |
| Type: | Private, Coeducational |
| Tuition: | $3500-$7050 |
| Grades: | 9–12 |
| Conference: | Western Big 6 |
| Song: | "Hail to the Pioneers" |
| Accreditation: | North Central Association of Colleges and Schools[1] |
| Rival: | Moline High School |
| Mascot: | Pioneer |
| Team Name: | Pioneers |
| Yearbook: | Pioneer |
| Publication: | Reflections (Literary Publication) |
| Newspaper: | Pioneer Press |
| Established: | 1949 |
| Enrollment: | 270[2] |
| Enrollment As Of: | 2021–2022 |
| Feeders: | Seton Catholic, Jordan Catholic, Our Lady of Grace Academy |
| Homepage: | Official website |
Alleman Catholic High School is a private, Catholic high school in Rock Island, Illinois. It is located in the Diocese of Peoria. It is the second largest Catholic high school in the Quad Cities.
Alleman High School was established in 1949 and named for Rev John George Alleman. Its first principal was Father John F. O'Connor.
Alleman High School competes in the Illinois High School Association and is a member school of the Western Big 6 Conference. Available for the male students are baseball, basketball, cross country, football, golf, soccer, tennis, track & field, and wrestling. Female students have cheerleading, basketball, cross country, the Emeralds dance team, soccer, softball, tennis, track & field, golf, and volleyball available. The school's mascot is the Pioneer.