| The King's Forest | 2333.87 ha | | — |
| Ickworth Park | 611.81 ha | | — |
| RSPB Lakenheath Fen RSPB | 294.73 ha | | — |
| Berners Heath | 211.61 ha | | — |
| Knettishall Heath Suffolk Wildlife Trust | 173.99 ha | | — |
| Lackford Lakes Suffolk Wildlife Trust | 172.52 ha | | — |
| Tuddenham Heath | 129.69 ha | | — |
| Icklingham Plains | 105.6 ha | | — |
| Deadman's Grave | 104.1 ha | | — |
| Thetford Heath | 95.24 ha | | — |
| Dalham Hall Estate | 94.98 ha | | — |
| Bradfield Woods National Nature Reserve Suffolk Wildlife Trust | 70.61 ha | 🐕 | — |
| Weather Heath | 69.61 ha | | — |
| Nowton Park | 67.97 ha | | — |
| Cavenham Heath | 66.9 ha | | — |
| Horn Heath | 56.84 ha | | — |
| Maidscross Hill | 54.07 ha | | — |
| West Stow Country Park West Suffolk Council | 49.93 ha | | — |
| Warren Hill | 37.33 ha | | — |
| Market Weston Fen Suffolk Wildlife Trust | 36.4 ha | | — |
| Stallode Wash SSSI Natural England | 31.63 ha | | — |
| Branches Park Estate | 25.53 ha | | — |
| Hardwick Heath | 24.49 ha | | — |
| Red Lodge Heath | 20.73 ha | | — |
| Aspel Close Local Nature Reserve | 20.36 ha | | — |
| West Town Park | 17.66 ha | | — |
| Wangford Warren | 14.58 ha | | — |
| Barton Mills Valley Nature Reserve | 11.37 ha | | — |
| Norah Hanbury-Kelk Nature Reserve Suffolk Wildlife Trust | 7.85 ha | | — |
| Clare Castle Country Park | 7.81 ha | | — |
| Clare Common | 7.39 ha | | — |
| Reeves Meadow Little Ouse Headwaters Project | 6.53 ha | | — |
| The Severals | 6.3 ha | | — |
| Natterer's Wood Woodland Ways | 5.87 ha | | — |
| Webbs Fen Little Ouse Headwaters Project | 5.6 ha | | — |
| Abbey Gardens | 5.49 ha | | — |
| Thelnetham Old Fen Suffolk Wildlife Trust | 5.23 ha | | — |
| Millfields County Wildlife Site | 4.69 ha | | — |
| Flying Fortress Park | 4.54 ha | | — |
| No Man's Meadows Local Nature Reserve | 4.44 ha | | — |
| Haverhill Recreation Ground | 4.31 ha | | — |
| Parker's Piece Little Ouse Headwaters Project | 4.21 ha | | — |
| Heath Wood | 4.03 ha | | — |
| Gainsborough Recreation Ground St Edmundsbury (West Suffolk Council) | 3.96 ha | | — |
| Ten Acre Field | 3.43 ha | | — |
| Studlands Park | 3.15 ha | | — |
| Bugs Hole | 3.08 ha | | — |
| Pashford Poors Fen | 2.92 ha | | — |
| Thelnetham Middle Fen Suffolk Wildlife Trust | 2.7 ha | | — |
| Oak Tree Fen Little Ouse Headwaters Project | 2.49 ha | | — |
| New Fen Little Ouse Headwaters Project | 2.19 ha | | — |
| Aggie's Piece (Barningham Pocket Park) | 1.43 ha | | — |
| Sid's Piece Stanton Woodland & Wildlife Action Group | 1.26 ha | | — |
| Walled Garden & Nursery | 1.22 ha | | — |
| Grove Park Community Gardens | 1.08 ha | | — |
| Market Weston Village Green | 1.02 ha | | — |
| Half Moon Park | 0.86 ha | | — |
| Bleyswycks Bank Little Ouse Headwaters Project | 0.79 ha | | — |
| The Green | 0.79 ha | | — |
| The Nuttery | 0.78 ha | | — |
| Memorial Hall Gardens | 0.64 ha | | — |
| The Orchard Brandon Town Council | 0.53 ha | | — |
| Burton Green | 0.46 ha | | — |
| Defender Park US Air Force | 0.46 ha | | — |
| Rex Graham Nature Reserve | 0.4 ha | | — |
| Wings of Liberty Memorial Park US Air Force | 0.27 ha | | — |
| Walled Garden | 0.21 ha | | — |
| Rex Graham Nature Reserve (Extension) | 0.06 ha | | — |
| Elm Close Wildlife Project Haverbury Housing Partnership | 0.05 ha | | — |
| St Mary's Square | 0.04 ha | | — |
| St Mary's Square | 0.04 ha | | — |
| Peace Garden | 0.01 ha | | — |
| Barton Mills Nature Reserve | — | | — |
| Eriswell Wild Flower Meadow | — | | — |
| Saxon Gate Nature Reserve | — | | — |