Located within Lewes District Council (with about half also in the South Downs National Park), the parish (pop. circa 300) covers 3.27 square miles in a long narrow strip, over chalk downland in the south through wooded and arable wealden land to the north. This historical arrangement, typical of neighbouring parishes, provided each with areas for grazing, forestry and raising of crops, with the main settlements positioned around the church. St Martins Church is the centre of a conservation area at Church Corner.
Local people share a strong interest in conservation through volunteer groups such as Footpaths Preservation Society, Mid Sussex Bridleways Group, the Monday Group and The Westmeston Jubilee Pathway Trust.
From highest areas of about 800ft above sea level near Ditchling Beacon, the land drops steeply to about 325ft and then undulates further north to an average of about 220ft.
The area is well served by a network of bridleways, footpaths and permissive paths. Riding, cycling and walking are popular with both locals and the increasing numbers of visitors to the area. The main vehicular route B2116 west/east gives access to the northern routes via Spatham Lane and Hundred Acre Lane. Railway access is at Hassocks to the west and Plumpton in the north east.
The parish is near to the western boundary of East Sussex and borders Ditchling to the west, convenient for the health centre, post office, pubs, café, pharmacy and small shops. Further west in Hassocks can be found a more comprehensive selection of services including supermarket, and banks. Westmeston has a farm shop in Middleton Common Lane, golf club in Spatham Lane and a parish hall on Lewes Road which opened in 2000 and is available for hire.
The ancient and attractive county town of Lewes is 7 miles away and is the centre for local government.
The Westmeston area, whilst rural with some agricultural and horticultural activity, is mainly residential with much of the land used for equestrian interests, both commercial and private.