Redwell Wood is a 52.8-hectare (130-acre) biological Site of Special Scientific Interest near South Mimms in Hertfordshire.

The local planning authority is split between Hertsmere Borough Council and Welwyn Hatfield District Council.

[1][2] The site has ancient and secondary woodland, heath and scrub.

The woodland canopy is dominated by pedunculate oak.

Ground flora include bluebells and enchanter’s-nightshade, while heathland species include heather and the rare creeping willow.