Cornwall Council (Cornish: Konsel Kernow [ˈkɔn.sɛl ˈkɛrnɔʊ]), known between 1889 and 2009 as Cornwall County Council (Cornish: Konteth Konsel Kernow), is the local authority which governs the non-metropolitan county of Cornwall in South West England. Since 2009 it has been a unitary authority, having taken over district-level functions when the duchy's districts were abolished. The non-metropolitan county of Cornwall is slightly smaller than the ceremonial county, which additionally includes the Isles of Scilly. The council's headquarters is Lys Kernow (also known as New County Hall) in Truro.

The council has been under no overall control since July 2024. Following the May 2025 election an administration of the Liberal Democrats and independents formed to run the council.

Elected county councils were established in 1889 under the Local Government Act 1888, taking over administrative functions previously carried out by unelected magistrates at the quarter sessions. The first elections to the county council were held in January 1889 and it formally came into being on 1 April 1889, on which day it held its first formal meeting at the Municipal Buildings in Truro. The first chairman of the council was William Edgcumbe, 4th Earl of Mount Edgcumbe, a Conservative peer.

In 1974, Cornwall was reclassified as a non-metropolitan county under the Local Government Act 1972. The lower tier of local government was reorganised as part of the same reforms. Until 1974 the lower tier of local government comprised numerous boroughs, urban districts and rural districts. In 1974 the lower tier of local government was reorganised and Cornwall was left with six districts: Caradon, Carrick, Kerrier, North Cornwall, Penwith, and Restormel.

On 1 April 2009, the six districts were abolished as part of the 2009 structural changes to local government in England and their functions were taken over by the county council, making it a unitary authority. As part of the 2009 reforms, the county council was given the option of omitting the word "county" from its name, which it took, becoming "Cornwall Council".

The campaign for Cornish devolution began in 2000 with the founding of the Cornish Constitutional Convention, a cross-party, cross-sector association that campaigns for devolution to Cornwall. In 2009 the Liberal Democrat MP Dan Rogerson introduced a bill in parliament seeking to take power from Whitehall and regional quangos and pass it to Cornwall Council, with the intention of making the council an assembly similar to the National Assembly for Wales. In November 2010 the Prime Minister, David Cameron, suggested in comments to the local press that his government would "devolve a lot of power to Cornwall – that will go to the Cornish unitary authority." In 2011, the then Deputy Prime Minister Nick Clegg said he would meet a cross party group, including the six Cornish MPs, to look at whether more powers could be devolved to Cornwall.

Some powers were eventually devolved from the government to Cornwall Council in 2015, relating to matters including bus franchising, education and apprenticeships, renewable energy and energy efficiency and integration of health and social care services. Further devolved powers were agreed in November 2023, including in relation to adult education and Cornish distinctiveness and promotion of the Cornish language.

Since 2009, Cornwall Council has provided both county-level and district-level services. The whole county is also divided into civil parishes, which form a second tier of local government.