| St Joseph's Catholic Primary School, Swf115201 | Primary | Good | 7.6% | 170 |
| St Katherine's Church of England Primary School115264 | Primary | Good | 9.5% | 220 |
| St Lawrence Church of England Primary School, Rowhedge115077 | Primary | Good | 19.7% | 223 |
| St Leonard's Church of England Primary School140180 | Primary | Good | 29.2% | 253 |
| St Luke's Catholic Academy139577 | Primary | Good | 14.6% | 239 |
| St Luke's Church of England Controlled Primary School115082 | Primary | Good | 10.6% | 265 |
| St Luke's Park Primary School149066 | Primary | Good | 16.2% | 139 |
| St Margaret's Church of England Academy, Bowers Gifford143453 | Primary | Good | 21.7% | 192 |
| St Margaret's Church of England Voluntary Controlled Primary School Toppesfield115071 | Primary | Good | 12.1% | 66 |
| St Margaret's Preparatory School115416 | Not applicable | — | — | 156 |
| St Mark's West Essex Catholic School137058 | Secondary | Good | 19.5% | 1,082 |
| St Martin's School Brentwood136875 | Secondary | Good | 12.9% | 1,711 |
| St Mary's Church of England Primary School147878 | Primary | Good | 32.3% | 62 |
| St Mary's Church of England Voluntary Aided Primary School115155 | Primary | Good | 17.6% | 222 |
| St Mary's Church of England Voluntary Aided Primary School, Burnham-on-Crouch115159 | Primary | Good | 14.2% | 240 |
| St Mary's Church of England Voluntary Aided Primary School, Hatfield Broad Oak115178 | Primary | Requires Improvement | 17.8% | 45 |
| St Mary's CofE Foundation Primary School115269 | Primary | Good | 20.2% | 262 |
| St Mary's School for Girls115394 | Not applicable | — | — | 419 |
| St Michael's Church of England Voluntary Aided Junior School115197 | Primary | Good | 21.2% | 231 |
| St Michael's Church of England Voluntary Aided Primary School115157 | Primary | Requires Improvement | 21.8% | 405 |
| St Michael's CofE Primary Academy, Ramsey151534 | Primary | Requires Improvement | 41.2% | 119 |
| St Michael's Primary School and Nursery, Colchester114817 | Primary | Good | 26.2% | 232 |
| St Nicholas Church of England Primary School149617 | Primary | Good | 11.4% | 140 |
| St Nicholas Church of England Primary School, Tillingham147413 | Primary | Good | 17.3% | 81 |
| St Osyth Church of England Primary School142775 | Primary | Good | 40.9% | 296 |
| St Peter's Catholic Primary School147282 | Primary | Outstanding | 5.5% | 417 |
| St Peter's Church of England Primary Academy, West Hanningfield151511 | Primary | Good | — | — |
| St Peter's Church of England Voluntary Aided Primary School, South Weald115164 | Primary | Outstanding | 2.2% | 455 |
| St Peter's Church of England Voluntary Controlled Primary School, Coggeshall115108 | Primary | Good | 13.9% | 338 |
| St Peter's Church of England Voluntary Controlled Primary School, Sible Hedingham115070 | Primary | Good | 13.9% | 216 |
| St Philomena's School115415 | Not applicable | — | — | 96 |
| St Pius X Catholic Primary School147404 | Primary | Good | 22.4% | 214 |
| St Teresa's Catholic Primary School145997 | Primary | Good | 27.2% | 184 |
| St Teresa's Catholic Primary School, Basildon139917 | Primary | Good | 15.7% | 216 |
| St Teresa's Catholic Primary School, Colchester138311 | Primary | Outstanding | 7.8% | 218 |
| St Thomas More Catholic Primary School, Saffron Walden137081 | Primary | Good | 2.4% | 208 |
| St Thomas More's Catholic Primary School, Colchester138164 | Primary | Outstanding | 3.9% | 205 |
| St Thomas of Canterbury Church of England Aided Primary School, Brentwood115179 | Primary | Good | 22.4% | 523 |
| St. George's School114704 | Primary | Good | 35.6% | 626 |
| Stambridge Primary School141656 | Primary | Good | 15.4% | 84 |
| Stanway Fiveways Primary School114764 | Primary | Good | 21.2% | 513 |
| Stanway Primary School114732 | Primary | Good | 16.6% | 404 |
| Stapleford Abbotts Primary Academy144881 | Primary | Good | 28.6% | 155 |
| Staples Road Primary School146001 | Primary | Good | 5.7% | 615 |
| Stebbing Primary School114888 | Primary | Good | 14.7% | 191 |
| Steeple Bumpstead Primary School145725 | Primary | Good | 9.8% | 184 |
| Stewards Academy - Science Specialist, Harlow137552 | Secondary | Requires Improvement | 33.6% | 989 |
| Stisted Church of England Primary Academy137544 | Primary | Outstanding | 9.8% | 102 |
| Stock Church of England Primary School115120 | Primary | Good | 12.4% | 209 |
| Stourview Church of England Primary Academy151532 | Primary | Requires Improvement | 68.2% | 22 |