Rook Clift is a 10.7-hectare (26-acre) biological Site of Special Scientific Interest east of South Harting in West Sussex. It is also a Special Area of Conservation.

A stream rises in this steep sided valley, which has semi-natural ancient woodland on its slopes. The canopy is dominated by a nationally scarce tree, large leaved lime, with other trees including beech and ash. The rich mollusc fauna includes Helicodonta obvoluta, which is a Red Data Book species.