The district also contains the towns of Burgess Hill and East Grinstead plus surrounding rural areas, including many villages.

The neighbouring districts are Crawley, Horsham, Brighton and Hove, Lewes, Wealden and Tandridge.

The name "Mid Sussex" was occasionally used for various parts of central Sussex prior to 1974, including as an alternative name for the Lewes constituency created under the Redistribution of Seats Act 1885, and as a joint water district established in 1907.

[9] The whole district is also covered by civil parishes, which form a third tier of local government.

The district council appoints one of its councillors to serve on the 27-person National Park Authority.

Homes owned by their occupants, with or without a loan, make up more than 85% of Mid Sussex housing.

The proportion of homes which were rented as investments by non-occupants was higher than several other semi-rural districts of Sussex, with 11.7% of housing stock speculatively acquired in this way or to provide for those unable to obtain mortgage finance and 1.0% was let out to residents on either public or private shared ownership schemes, close to the national average.