Rackenford and Knowstone Moors is a nature reserve of the Devon Wildlife Trust, situated about north-west of Tiverton, in Devon, England. The habitat is culm grassland.
The reserve is a Site of Special Scientific Interest and a Special Area of Conservation. Its area is .
Culm grassland is found in poorly drained lowland areas of acidic soil where there is high rainfall. The vegetation includes abundant purple moor grass and sharp-flowered rush.
Over the last century, over 90% of culm grassland has been lost. The remaining parts are mostly in fragmented areas in north Devon; the most extensive fragment is this reserve. The Trust endeavours to protect, re-establish and link together isolated sites of culm grassland. In the reserve there is light grazing by cattle and deer; the low-intensity land management, little changed from prehistoric times, allows a wide diversity of plant species.
In the wetter areas, besides purple moor grass and sharp-flowered rush, species include ragged-robin, meadowsweet and wild angelica; in waterlogged areas there is sphagnum moss and sundew. In dry areas there is saw-wort, thistles and heathers. The plants support many species of butterflies, such as small pearl-bordered fritillary, marbled white and dingy skipper; birds including curlew, snipe and reed bunting may be found.
On Knowstone Inner Moor there is saucer barrow, of the early Bronze Age: it is a mound, diameter and height up to , surrounded by a ditch and outer bank.