| Norton Cevc Primary School124710 | Primary | Good | 12.3% | 203 |
| Oa - Suffolk142820 | Not applicable | Good | 50.0% | 2 |
| Occold Primary School146173 | Primary | Good | 13.2% | 53 |
| Old Buckenham Hall School124873 | Not applicable | — | — | 199 |
| Old Newton Church of England Primary School143070 | Primary | Good | 15.7% | 70 |
| On Track Education Mildenhall127003 | Not applicable | — | — | 56 |
| One Sixth Form College142283 | 16 plus | — | 0.0% | 2,404 |
| OneSchool Global UK Colchester Campus134480 | Not applicable | — | — | 120 |
| Orford Church of England Primary School and Nursery150252 | Primary | Good | 32.4% | 34 |
| Ormiston Denes Academy139403 | Secondary | Good | 58.4% | 711 |
| Ormiston Endeavour Academy137674 | Secondary | Good | 31.5% | 793 |
| Ormiston Sudbury Academy138506 | Secondary | Needs attention | 35.5% | 710 |
| Orwell Park School124866 | Not applicable | — | — | 167 |
| Otley Primary School124602 | Primary | Good | 17.6% | 51 |
| Oulton Broad Primary School124676 | Primary | Outstanding | 19.8% | 378 |
| Paddocks Primary School124565 | Primary | Good | 18.4% | 179 |
| Pakefield High School146909 | Secondary | Good | 38.4% | 679 |
| Pakefield Primary School141640 | Primary | Needs attention | 18.4% | 274 |
| Palgrave Church of England Primary School143071 | Primary | Good | 8.2% | 85 |
| Parkside Academy142801 | Not applicable | Good | 80.0% | 5 |
| Phoenix St Peter Academy141983 | Primary | Good | 56.0% | 109 |
| Piper's Vale Primary - A Paradigm Academy145118 | Primary | Good | 51.2% | 361 |
| Place Farm Primary Academy138161 | Primary | Good | 30.7% | 416 |
| Poplars Community Primary School145541 | Primary | Requires Improvement | 47.3% | 260 |
| Pot Kiln Primary School124536 | Primary | Good | 28.8% | 236 |
| Priory School137433 | Not applicable | Outstanding | 49.8% | 241 |
| Pushforward Primary School152350 | Not applicable | — | — | — |
| Pushforward Secondary School152344 | Not applicable | — | — | — |
| Ranelagh Primary School124645 | Primary | Good | 34.3% | 281 |
| Rattlesden Church of England Primary Academy142554 | Primary | Good | 14.1% | 135 |
| Ravensmere Infant School143491 | Primary | Good | 21.2% | 52 |
| Ravenswood Community Primary School151105 | Primary | Good | 30.6% | 385 |
| Red Oak Primary School140573 | Primary | Good | 40.4% | 420 |
| Redstone Hall School152347 | Not applicable | — | — | — |
| Rendlesham Primary School145795 | Primary | Good | 9.6% | 277 |
| Reydon Primary School141702 | Primary | Good | 28.6% | 168 |
| Ringsfield Church of England Primary School144849 | Primary | Good | 9.9% | 118 |
| Ringshall School147509 | Primary | Good | 12.0% | 117 |
| Risby Church of England Voluntary Controlled Primary School124712 | Primary | Good | 7.4% | 203 |
| Riverwalk School146418 | Not applicable | Good | 40.8% | 217 |
| Roman Hill Primary School145559 | Primary | Requires Improvement | 51.1% | 375 |
| Rose Hill Primary145540 | Primary | Good | 29.7% | 259 |
| Rougham Church of England Primary School145237 | Primary | Good | 11.2% | 196 |
| Royal Hospital School124889 | Not applicable | — | — | 495 |
| Rushmere Hall Primary School148414 | Primary | Good | 13.1% | 506 |
| Saint Felix School124868 | Not applicable | — | — | 235 |
| Samuel Ward Academy136322 | Secondary | Good | 17.7% | 1,076 |
| Sandlings Primary School124685 | Primary | Good | 6.1% | 82 |
| Saxmundham Primary School146494 | Primary | Good | 40.6% | 252 |
| Sebert Wood Community Primary School124682 | Primary | Good | 11.5% | 374 |