| Saint Mary's High School | |
| Streetaddress: | 51 Clapham Avenue |
| Zipcode: | 11030 |
| Founder: | Sisters, Servants of the Immaculate Heart of Mary and the Marist Brothers of the Schools |
| President: | Elias Carr |
| Principal: | Gerard Buckley |
| Ceeb: | 333015 |
| School Code: | 699 |
| Fees: | $350 Registration Deposit |
| Tuition: | $12,500 (2020-2021) |
| Campus Size: | Medium |
| Athletics: | Multiple |
| Conference: | Nassau/Suffolk Catholic High School Athletic Association (NSCHSAA) |
| Motto: | Omina ad Jesum per Mariam |
| Motto Translation: | Everything to Jesus through Mary |
| Accreditation: | Middle States Association of Colleges and Schools[1] |
| Sports: | Soccer, Basketball, Lacrosse, Swimming, Hockey, Bowling, Badminton, Tennis, Volleyball, Baseball, Softball, etc. |
| Patron: | Saint Mary |
| Nickname: | Gaels |
| Yearbook: | Gael |
| Newspaper: | The Magnificat |
| Established: | 1949 |
| Alumni: | Alumni Website |
| Enrollment: | 455 |
| Enrollment As Of: | 2019-2020 |
| Communities: | Arch Diocese of New York, Diocese of Brooklyn and Diocese of Rockville Centre |
| Homepage: | School Website |
Saint Mary's High School is a private Catholic high school in Manhasset, New York. St. Mary's parish is part of the Roman Catholic Diocese of Rockville Centre yet the High School serves families of the Roman Catholic Archdiocese of New York, the Diocese of Brooklyn and the Diocese of Rockville Centre. It is located off Northern Boulevard at 51 Clapham Avenue, Manhasset, near the Miracle Mile. St. Mary's Men's Varsity Ice Hockey is the all-time leader in New York State Championships, winning consecutive titles from 1994-2006. The Girls Varsity Basketball team won consecutive New York State Championship titles in 2021-2022 and 2022-2023.
Starting in 2011 students are issued an iPad configured for educational use.[2] Starting in 2018, students are issued a Chromebook replacing their iPad.[3] Personal devices are not allowed including phones, media players, and computers. In September 2021, the school staff includes several members of the Dominican Sisters of Mary, Mother of the Eucharist.