An election to Mayo County Council took place on 5 June 2009 as part of that year's Irish local elections. 31 councillors were elected from six local electoral areas (LEAs) for a five-year term of office on the electoral system of proportional representation by means of the single transferable vote (PR-STV). https://web.archive.org/web/20140508030329/http://www.environ.ie/en/LocalGovernment/Voting/LocalElections/PublicationsDocuments/FileDownLoad%2C23415%2Cen.pdf