Warren Bank is a 3.1-hectare (7.7-acre) biological Site of Special Scientific Interest south-east of Wallingford in Oxfordshire.

[1][2] It is managed by the Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust.

[3] This steeply sloping site has unimproved chalk grassland and scrub.

There is a rich variety of flora, including horseshoe vetch, chalk milkwort and bee orchid.

There are also many insects, with butterflies such as dark green fritillary and green hairstreak.