RSPB Arne reserve is a 1250 acre nature reserve, run by the RSPB, overlooking Poole Harbour and adjacent to the village of Arne, in Dorset.

The reserve opened in 1966 and is chiefly lowland heath. The rare Dorest Heath (Erica ciliaris) can be found here and Dartford Warblers can be seen. It also has acid grassland, salt marsh and woodland, with reedbeds adjoining the mudflats of the harbour. Other important species include Nightjar, Woodlark and, on the mudflats, Spoonbill.

Over 500 species of vascular plant have been recorded on the reserve, since 1966.

The reserve overlooks Poole Harbour where, in winter, you can watch large numbers of wading birds ducks and geese including black-tailed godwits, brent geese and red-breasted mergansers.