Chapel Common is a 101-hectare (250-acre) biological Site of Special Scientific Interest west of Fernhurst in West Sussex. A Roman road through the common is a Scheduled Monument.

Most of the common is dry heathland but there are also areas of woodland, grassland and scrub. Heathland birds include three internationally important species listed on Annex I of the EU Birds Directive, woodlark, nightjar and Dartford warbler. The site also has rare and scarce invertebrates.

Several public footpaths cross the common.