| Pakefield High School146909 | Secondary | Good | 38.9% | 701 |
| Paddocks Primary School124565 | Primary | Good | 17.8% | 185 |
| Oulton Broad Primary School124676 | Primary | Outstanding | 19.8% | 373 |
| Otley Primary School124602 | Primary | Good | 17.9% | 57 |
| Orwell Park School124866 | Not applicable | — | — | 210 |
| Ormiston Sudbury Academy138506 | Secondary | Requires Improvement | 32.9% | 679 |
| Ormiston Endeavour Academy137674 | Secondary | Good | 31.5% | 739 |
| Ormiston Denes Academy139403 | Secondary | Good | 55.6% | 730 |
| Orford Church of England Primary School and Nursery150252 | Primary | Good | 29.8% | 47 |
| OneSchool Global UK Colchester Campus134480 | Not applicable | — | — | 131 |
| One Sixth Form College142283 | 16 plus | — | 0.0% | 2,338 |
| On Track Education Mildenhall127003 | Not applicable | — | — | 43 |
| Old Newton Church of England Primary School143070 | Primary | Good | 15.7% | 70 |
| Old Buckenham Hall School124873 | Not applicable | — | — | 190 |
| Occold Primary School146173 | Primary | Good | 10.4% | 48 |
| Oa - Suffolk142820 | Not applicable | Good | 60.0% | 10 |
| Norton Cevc Primary School124710 | Primary | Good | 10.2% | 205 |
| Northgate High School124840 | Secondary | Good | 18.1% | 1,709 |
| Northfield St Nicholas Primary Academy142016 | Primary | Good | 49.4% | 341 |
| Newmarket Academy140669 | Secondary | Good | 20.5% | 813 |
| New Skill Centre146332 | Not applicable | — | — | 60 |
| New Cangle Community Primary School124537 | Primary | Good | 13.8% | 210 |
| Ness Point School148425 | Not applicable | — | — | 25 |
| Nayland Primary School124543 | Primary | Good | 7.9% | 203 |
| Nacton Church of England Primary School142994 | Primary | Good | 10.8% | 93 |
| Murrayfield Primary - A Paradigm Academy143550 | Primary | Good | 46.9% | 407 |
| Moulton Church of England Voluntary Controlled Primary School124709 | Primary | Outstanding | 11.9% | 210 |
| Morland Church of England Primary School145851 | Primary | Good | 38.3% | 358 |
| Mildenhall College Academy139867 | Secondary | Good | 24.5% | 1,338 |
| Middleton Community Primary School143806 | Primary | Good | 26.3% | 19 |
| Mendlesham Primary School143361 | Primary | Good | 21.7% | 106 |
| Mendham Primary School143069 | Primary | Good | 28.6% | 63 |
| Melton Primary School124597 | Primary | Good | 31.6% | 174 |
| Mellis Church of England Primary School143807 | Primary | Good | 6.8% | 147 |
| Martlesham Primary Academy142018 | Primary | Good | 26.7% | 116 |
| Long Melford Church of England Primary School143147 | Primary | Good | 21.0% | 219 |
| Leiston Primary School141554 | Primary | Requires Improvement | 37.3% | 396 |
| Learning Support, Western Area Education Office133238 | Not applicable | — | — | — |
| Learning Support, Southern Area Education Office133237 | Not applicable | — | — | — |
| Learning Support, Northern Area Education Office133239 | Not applicable | — | — | — |
| Lavenham Community Primary School124540 | Primary | Good | 21.2% | 118 |
| Laureate Community Academy142993 | Primary | Good | 15.8% | 241 |
| Langer Primary Academy138117 | Primary | Good | 45.5% | 157 |
| Lakenheath Community Primary School124539 | Primary | Good | 18.5% | 260 |
| Kyson Primary School152031 | Primary | Good | — | — |
| Kingsfleet Primary School124627 | Primary | Good | 18.2% | 192 |
| King Edward Vi Cevc School124856 | Secondary | Good | 19.9% | 1,199 |
| Kessingland Church of England Primary Academy141172 | Primary | Good | 45.1% | 211 |
| Kesgrave High School136969 | Secondary | Good | 14.5% | 1,858 |
| Kersey Church of England Primary School148846 | Primary | Good | 27.5% | 40 |