| St. Mary High School | |
| Streetaddress: | 812 North State Avenue |
| City: | Dell Rapids |
| State: | South Dakota |
| County: | (Minnehaha County) |
| Zipcode: | 57022 |
| Country: | USA |
| Coordinates: | 43.8278°N -96.7081°W |
| Religion: | Roman Catholic |
| Superintendent: | Fr. Shane D. Stevens |
| Principal: | Casey Michel |
| Type: | Private, Coeducational |
| Grades: | 9–12 |
| Conference: | Dakota Valley Conference |
| Fightsong: | On Wisconsin |
| Mascot: | Cardinal |
| Team Name: | Cardinals |
| Established: | 1910 |
| Free Label3: | Athletic Director |
| Free Text3: | Casey Michel |
| Homepage: | http://www.drstmary.org |
St. Mary High School is a private, Roman Catholic high school in Dell Rapids, South Dakota. It is located in the Roman Catholic Diocese of Sioux Falls. School colors for St. Mary High School are Red and White. The school's mascot is the Cardinal.