| Nene Wetlands Nature Reserve The Wildlife Trust BCN | 277.57 ha | | — |
| Stanwick Lakes | 255.58 ha | | — |
| Irchester Country Park | 78.57 ha | | — |
| Titchmarsh NR | 77.43 ha | | — |
| Lilford Park | 76.6 ha | | — |
| Wicksteed Park | 70.25 ha | | — |
| Sywell Country Park | 57.54 ha | | — |
| Drayton Park | 56.08 ha | | — |
| Twywell Hills and Dales | 54.69 ha | | — |
| Summer Leys Local Nature Reserve The Wildlife Trust for Bedfordshire, Cambridgeshire, Northamptonshire and Peterborough | 47.86 ha | | — |
| Bozeat Quarry Northants Wildlife Trust | 44.02 ha | | — |
| East Carlton Countryside Park | 34.72 ha | | — |
| Polebrook Airfield NR | 33.58 ha | | — |
| Desborough Greenspace Kettering Borough Council | 33.16 ha | | — |
| Ditchford Lakes and Meadows | 32.21 ha | | — |
| King's Wood | 31.0 ha | | — |
| Higham Ferrers Pits and Wilson's Pits | 30.89 ha | | — |
| Glapthorn Cow Pastures NR | 29.14 ha | | — |
| Short Wood NR | 26.15 ha | | — |
| Southwick Wood NR | 23.4 ha | | — |
| West Glebe Park | 19.82 ha | | — |
| Weldon Woodland Park North Northamptonshire Council | 17.82 ha | | — |
| Fermyn Woods Country Park | 15.23 ha | | — |
| Barnwell Country Park | 15.15 ha | | — |
| Hall Park | 12.74 ha | | — |
| Queensway Park Area | 12.59 ha | | — |
| Warth Park Country Park (North) | 11.87 ha | | — |
| Warth Park Country Park (South) | 11.03 ha | | — |
| Oakley Park | 9.81 ha | | — |
| Stanwell Lake Greenbelt Park | 9.73 ha | | — |
| Stanton Cross Town Park | 9.29 ha | | — |
| Higham Ferrers Riverside Park | 9.09 ha | | — |
| Stanwell Park | 8.61 ha | | — |
| Castle Fields | 6.38 ha | | — |
| Ise Valley Parklands | 5.83 ha | | — |
| Manor Park | 5.44 ha | | — |
| Croyland Park Recreation Field | 5.4 ha | | — |
| Croyland Park | 5.33 ha | | — |
| Dale End Park | 4.79 ha | | — |
| ' Recreation Ground | 4.67 ha | | — |
| North Park | 4.61 ha | | — |
| Eastfield Park | 4.41 ha | | — |
| Dodhaws Wood NR | 4.24 ha | | — |
| Grange Park | 4.16 ha | | — |
| Stanwick Pocket Park | 3.99 ha | | — |
| Rockingham Road Park | 3.93 ha | | — |
| Bassett's Close Park | 3.9 ha | | — |
| Desborough Pocket Park | 3.81 ha | | — |
| Burton Latimer Pocket Park | 3.77 ha | | — |
| Kings Cliffe Village Field | 3.69 ha | | — |
| Croyland park | 3.45 ha | | — |
| Swanspool Gardens | 3.28 ha | | — |
| Croyland Gardens | 2.76 ha | | — |
| Recreational area | 2.72 ha | | — |
| Meadow Road Park | 2.36 ha | | — |
| Manor Park | 2.35 ha | | — |
| Finedon Cally Banks | 2.23 ha | | — |
| Kings Cliffe Meadow | 1.99 ha | | — |
| Wilby Youth Football Club and Park | 1.99 ha | | — |
| Croyland Park Football Field | 1.89 ha | | — |
| Rothwell Gullet | 1.79 ha | | — |
| Glenvale Green | 1.73 ha | | — |
| Gray's Field | 1.67 ha | | — |
| Grafton Street Park | 1.56 ha | | — |
| Kings Cliffe Common | 1.55 ha | | — |
| Pocket Park | 1.4 ha | | — |
| Coronation Park | 1.37 ha | | — |
| Croyland Gardens | 1.26 ha | | — |
| Croyland Park Area | 1.16 ha | | — |
| Les O'Dell Park | 1.14 ha | | — |
| Blatherwycke Walled Garden | 1.06 ha | | — |
| Peace Memorial Park | 1.04 ha | | — |
| Raunds Pocket Park Raunds Town Council | 0.62 ha | | — |
| Millenium Green | 0.36 ha | | — |
| Kingsmead Local Wildlife Site East Northants District Council | 0.14 ha | | — |
| The Rambler's Rest Chartered Institute of Procurement and Supply | 0.05 ha | | — |
| BCN Wildlife Discovery Centre The Wildlife Trust BCN | — | | — |
| Ring Haw Field Station Bedfordshire, Cambridgeshire, Northamptonshire Wildlife Trust | — | | — |