This is a list of settlements in West Sussex by population based on the results of the 2011 census. The next United Kingdom census took place in 2021. In 2011, there were 20 built-up area subdivisions with 5,000 or more inhabitants in West Sussex, shown in the table below.
| No. | Settlement | Borough/District | Population | Notes | ||
|---|---|---|---|---|---|---|
| (2001)[1] | (2011)[2] | |||||
| 1 | Worthing | Worthing | 101,929 | 109,120 | Includes Ferring | |
| 2 | Crawley | Crawley | 99,660 | 106,943 | ||
| 3 | Bognor Regis | Arun | 61,800 | 63,885 | Includes Flansham, Middleton-on-Sea, Pagham. Excludes Bilsham, Colworth, Shripney | |
| 4 | Littlehampton | Arun | 50,930 | 55,706 | Includes Angmering, Hammerpot, West Kingston, Wick. Excludes Lyminster, Poling | |
| 5 | Shoreham-by-Sea | Adur | 47,020 | 48,487 | Includes Sompting | |
| 6 | Horsham | Horsham | 44,890 | 48,041 | Includes Roffey | |
| 7 | Haywards Heath | Mid Sussex | 29,110 | 33,845 | Includes Bolnore Village, Lindfield. Excludes Cuckfield, Scaynes Hill, Walstead | |
| 8 | Burgess Hill | Mid Sussex | 29,388 | 30,635 | Includes World's End. Excludes Goddards Green, Wivelsfield | |
| 9 | East Grinstead | Mid Sussex | 26,490 | 29,084 | Includes Ashurst Wood, Ashplats, Felbridge, Imberley. Excludes Crawley Down, Domewood, Dormans Park, Effington Park, Forest Row | |
| 10 | Chichester | Chichester | 25,520 | 28,657 | Includes Stockbridge, Summerdale. Excludes Apuldram, Donnington, Fishbourne, Hunston, Lavant, Merston, North Mundham, Runction, Westhampnett | |
| 11 | Hurstpierpoint | Mid Sussex | 11,173 | 12,730 | Includes Hassocks | |
| 12 | Southwick | Adur | 11,513 | 11,551 | ||
| 13 | Selsey | Chichester | 9,720 | 10,550 | Excludes Church Norton | |
| 14 | Westergate | Arun | 9,099 | 9,783 | Includes Barnham, Eastergate, Fontwell, Walberton. Excludes Aldingbourne, Norton, Slindon, Yapton | |
| 15 | Southwater | Horsham | 8,298 | 8,692 | ||
| 16 | Storrington | Horsham | 7,730 | 8,618 | Includes Heath Common. Excludes Ashington, Rock, Sullington, Washington, West Wantley | |
| 17 | West Chiltington Common | Horsham | 6,940 | 7,474 | Includes Pulborough | |
| 18 | Billingshurst | Horsham | 5,460 | 6,911 | ||
| 19 | Steyning | Horsham | 6,365 | 6,557 | Excludes Annington, Bramber | |
| 20 | East Wittering | Chichester | 5,127 | 5,647 | Includes Bracklesham. Excludes Earnley | |
| Midhurst | Chichester | 4,889 | 4,914 | Excludes Easebourne, West Lavington | ||
| Henfield | Horsham | 4,527 | 4,799 | Excludes West End, Woodmancote | ||
| Crawley Down | Mid Sussex | 4,631 | 4,598 | Excludes Turners Hill | ||