The 2021 Suffolk County Council election took place on 6 May 2021 as part of the 2021 local elections in the United Kingdom. All 75 councillors were elected from 63 electoral divisions, which return either one or two county councillors each, by first-past-the-post voting, for a four-year term of office.
Voters who live in divisions which elect two councillors (12 divisions) are entitled to cast a maximum of two votes, while those living in divisions only electing one councillor (51 divisions) are only entitled to cast one vote.
The council is subject to a Local Government Boundary Commission for England review where it is proposed to reduce the number of councillors from 75 to 70. The recommendations were due to be implemented at this election but were deferred to the scheduled 2025 Suffolk County Council election owing to the COVID-19 pandemic.
In between the 2017 election and the 2021 election, the following council seats changed hands outside of by-elections:
The county saw a marked contrast between its rural and urban areas. The ruling Conservative administration made 8 gains across Bury St Edmunds, Ipswich and Lowestoft, but lost 5 divisions in rural Suffolk that it had won four years earlier and was traditionally stronger. The Green Party replaced Labour as the second largest party, and the latter were subsequently relegated to 5 seats. The Liberal Democrats continued their descent after making losses in 2013 and 2017, with a further loss. The Independents also finished one seat lower than 2017. With 55 seats, the Conservatives were subsequently returned for a fifth term in office and scored their joint second best number of seats (equalling 2009) since the council was created in 1973.
|-bgcolor=#F6F6F6 | colspan=2 style="text-align: right; margin-right: 1em" | Total | style="text-align: right;" | 289 | style="text-align: right;" | 75 | colspan=5 | | style="text-align: right;" | 260,233 | style="text-align: right;" | |-
Matthew Hicks (Thredling) was re-elected leader of the Conservative Group, with Richard Rout (Hardwick) as his deputy.
Andrew Stringer (Upper Gipping) was elected leader of the joint Green, Lib Dem and Independent group, with Robert Lindsay (Cosford) as his deputy.
Sarah Adams (St John's) was re-elected leader of the Labour Group, with Sandy Martin (Rushmere) as her deputy.
Matthew Hicks the leader of the Conservative group was duly elected leader of the council and formed a Conservative administration.
Summary
Division results
Division results
Division results
Division results
Division results
*Note: Nettleton won a seat standing as an independent at the previous election.