| St. Helen Catholic School | Georgetown | Private school | PK–8 | 0 |
| St. Helen Catholic School | Pearland | Private school | PK–8 | 0 |
| St. Helenas Episcopal School | Boerne | Private school | PK–5 | 0 |
| St. Ignatius College Prep | Fort Worth | Private school | 9–12 | 0 |
| St. Ignatius Loyola Early Childhood Center | Spring | Private school | PK–K | 0 |
| St. Ignatius Martyr Catholic School | Austin | Private school | K–8 | 0 |
| St. James Catholic School | Seguin | Private school | K–8 | 0 |
| St. James Day School | Texarkana | Private school | PK–8 | 0 |
| St. James Episcopal School | Del Rio | Private school | PK–5 | 0 |
| St. James Episcopal School | Corpus Christi | Private school | PK–8 | 0 |
| St. James Episcopal School Of Dallas | Dallas | Private school | PK–K | 0 |
| St. James The Apostle School | San Antonio | Private school | PK–8 | 0 |
| St. Jerome Catholic School | Houston | Private school | K–8 | 0 |
| St. John Berchmans School | San Antonio | Private school | K–8 | 0 |
| St. John Bosco School | San Antonio | Private school | PK–8 | 0 |
| St. John Lutheran Preschool Kinder/bridge | Hamilton | Private school | PK–K | 0 |
| St. John Paul II High School | Corpus Christi | Private school | 9–12 | 0 |
| St. John The Apostle Catholic | North Richland Hills | Private school | K–8 | 0 |
| St. John Xxiii College Prreparatory | Katy | Private school | 9–12 | 0 |
| St. Johns Episcopal Day School | McAllen | Private school | PK–6 | 0 |
| St. Johns Episcopal School | Abilene | Private school | PK–5 | 0 |
| St. Joseph Academy | Brownsville | Private school | 7–12 | 0 |
| St. Joseph Catholic Academy | Killeen | Private school | PK–9 | 0 |
| St. Joseph Catholic Elementary & Montessotir School | Amarillo | Private school | PK–5 | 0 |
| St. Joseph Catholic School | Edinburg | Private school | PK–8 | 0 |
| St. Joseph Catholic School | Arlington | Private school | PK–8 | 0 |
| St. Joseph Catholic School | Baytown | Private school | PK–8 | 0 |
| St. Joseph Catholic School | Richardson | Private school | PK–8 | 0 |
| St. Joseph Catholic School | Waxahachie | Private school | PK–8 | 0 |
| St. Joseph Catholic School | Bryan | Private school | PK–12 | 0 |
| St. Joseph Catholic School - Elementary Campus | Bryan | Private school | PK–5 | 0 |
| St. Joseph Elementary School | Yoakum | Private school | PK–8 | 0 |
| St. Joseph High School | Victoria | Private school | 9–12 | 0 |
| St. Louis Catholic School | Austin | Private school | PK–8 | 0 |
| St. Louis Catholic School | Waco | Private school | PK–12 | 0 |
| St. Louis Catholic School | Castroville | Private school | K–5 | 0 |
| St. Luke Catholic School | San Antonio | Private school | PK–8 | 0 |
| St. Lukes Episcopal School | San Antonio | Private school | PK–8 | 0 |
| St. Luke's Preschool | Lubbock | Private school | PK–K | 0 |
| St. Mark Lutheran School | Houston | Private school | PK–8 | 0 |
| St. Mark's Episcopal School | Houston | Private school | PK–8 | 0 |
| St. Marks School | El Paso | Private school | PK–8 | 0 |
| St. Martha Catholic School | Kingwood | Private school | PK–8 | 0 |
| St. Martin De Porres Catholic School | Prosper | Private school | PK–8 | 0 |
| St. Mary Catholic School | League City | Private school | PK–8 | 0 |
| St. Mary Catholic School | Orange | Private school | PK–8 | 0 |
| St. Mary Magdalene School | Humble | Private school | PK–8 | 0 |
| St. Mary Of Carmel School | Dallas | Private school | PK–8 | 0 |
| St. Mary Of The Purification Catholic School | Houston | Private school | K–8 | 0 |
| St. Mary S Catholic School | Longview | Private school | PK–12 | 0 |