1918–1974: The Municipal Boroughs of Yeovil and Chard, the Urban Districts of Crewkerne and Ilminster, the Rural Districts of Chard, Langport, Yeovil.
1974–1983: As 1918 but with redrawn boundaries.
From 1918 until 1983 the seats of the zone today forming the administrative county were one fewer. Before 1983 the seat took in Martock, Somerton and Ilchester, these totalling about 11,000 residents today, but they joined the Somerton and Frome new seat.
1983–1997: The District of Yeovil wards of Blackdown, Chard North East, Chard North West, Chard Parish, Chard South East, Chard South West, Chinnock, Coker, Crewkerne Town, Dowlish, Egwood, Hazelbury, Houndstone, Ilminster Town, Lynches, Mudford, Neroche, St Michael's, South Petherton, Stoke, Windwhistle, Yeovil Central, Yeovil East, Yeovil North, Yeovil Preston, Yeovil South, Yeovil West.
1997–2010: The District of South Somerset wards of Blackdown, Chard Avishayes, Chard Combe, Chard Crimchard, Chard Holyrood, Chard Jocelyn, Coker, Crewkerne, Egwood, Hamdon, Houndstone, Ilminster, Mudford, Neroche, Parrett, St Michael's, South Petherton, Tatworth and Forton, Windwhistle, Yeovil Central, Yeovil East, Yeovil Preston, Yeovil South, Yeovil West, Yeovil Without.
Ilchester (with a populace of a large village) is restored to the seat since 2010 and the ward that includes Brypmton has been added.[2]
2010–2024: The District of South Somerset wards of Blackdown, Brympton, Chard Avishayes, Chard Combe, Chard Crimchard, Chard Holyrood, Chard Jocelyn, Coker, Crewkerne, Egwood, Hamdon, Ilminster, Ivelchester, Neroche, Parrett, St Michael's, South Petherton, Tatworth and Forton, Windwhistle, Yeovil Central, Yeovil East, Yeovil South, Yeovil West, Yeovil Without.
The District of South Somerset wards of: Blackdown & Tatworth; Brympton; Chard Avishayes; Chard Combe; Chard Crimchard; Chard Holyrood; Chard Jocelyn; Coker; Crewkerne; Eggwood; Ilminster; Neroche; Parrett; South Petherton; Windwhistle; Yeovil College; Yeovil Lyde; Yeovil Summerlands; Yeovil Westland; Yeovil Without.[3]
In order to bring the electorate within the permitted range, rural areas to the north of the town of Yeovil will be transferred to the new constituency of Glastonbury and Somerton.
With effect from 1 April 2023, the District of South Somerset was abolished and absorbed into the new unitary authority of Somerset.[4] The constituency will therefore now comprise the following electoral divisions of Somerset from the 2024 general election:
From 1918 until 1983, Yeovil always returned a Conservative MP (though by only narrow margins over Labour in the 1940s and 1950s). There then followed a period of over 30 years during which the seat was represented by a member of the Liberal Party or their successors, the Liberal Democrats; firstly former leader Paddy Ashdown (1983–2001) and then former Chief Secretary to the Treasury David Laws (2001 to 2015).[6] At the 2015 election, the seat returned to its former Conservative allegiance as Marcus Fysh defeated Laws by over 5,000 votes.[7]
The South Somerset district voted 57% to leave the European Union, and academic analysis estimates that Yeovil itself voted 59% to leave.[8] There was a swing of 7.7% away from the pro-Remain Liberal Democrats towards the pro-Leave Conservatives, which made the seat much safer in 2017, Marcus Fysh's majority increasing to just under 15,000. In 2019 the voters slightly increased this majority (to over 16,000).
Another general election was required to take place before the end of 1940. The political parties had been making preparations for an election to take place and by the Autumn of 1939, the following candidates had been selected;