From 1894 the administrative county was divided into municipal boroughs, urban districts and rural districts:
- Boroughs: Aldeburgh, Beccles, Eye, Lowestoft, Southwold
- Urban districts: Bungay (created 1910), Felixstowe and Walton, (renamed Felixstowe 1914), Halesworth (created 1900), Leiston-cum-Sizewell (created 1895), Oulton Broad (created 1904, abolished 1919), Saxmundham (created 1900), Stowmarket, Woodbridge
- Rural districts created in 1894: Blything, Bosmere and Claydon, East Stow, Hartismere, Hoxne, Mutford and Lothingland, Plomesgate, Samford, Wangford, Woodbridge
The rural districts were further subdivided into civil parishes.
In 2018 a new East Suffolk district was created by the abolition and merger of Waveney and Suffolk Coastal districts. The new district, came into effect on 1 April 2019.
- ^ Historic England. "County Hall Main Entrance Block, Ipswich (1207685)". National Heritage List for England. Retrieved 13 August 2019.
- ^ "Ipswich mayor refutes Bury St Edmunds' county town title claim as 'not in the same league'". East Anglia Times. 28 February 2017. Retrieved 8 October 2019.
- ^ "East Suffolk". Vision of Britain. Retrieved 8 October 2019.
- ^ Ministry of Housing, Communities and Local Government (24 May 2018). "The East Suffolk (Local Government Changes) Order 2018". legislation.gov.uk. Retrieved 12 August 2018.
Coordinates: 52°12′N 1°15′E / 52.20°N 1.25°E