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Instant-runoff voting (IRV), also known as ranked-choice voting (RCV), preferential voting (PV), or the alternative vote (AV),^[1] is a multi-round elimination method where the loser of each round is determined by the first-past-the-post method.^[2]^[3] In academic contexts, the term instant-runoff voting is generally preferred as it does not run the risk of conflating the method with methods of ranked voting in general.

IRV is counted in steps. In each step, IRV looks at every ballot's top non-eliminated candidate and eliminates the candidate with the fewest top rankings. It falls into the plurality-with-elimination family of voting systems, alongside first-past-the-post and systems based on runoff elections. It contrasts with the rated voting and majority-rule methods of elections.

IRV has been used in Australia,^[4] for the president of Ireland,^[5] and for the National Parliament of Papua New Guinea.^[6]

^ "Alternative Vote". www.electoral-reform.org.uk. Retrieved 30 May 2019.
^ Robert, Henry (2011). Robert's Rules of Order Newly Revised (11th ed.). Da Capo Press. pp. 425–428. ISBN 978-0-306-82020-5.
^ "Types of Voting Systems". Mtholyoke.edu. 8 April 2005. Archived from the original on 8 July 2006. Retrieved 6 May 2010.
^ "Australian Electoral Commission". Aec.gov.au. 23 April 2014. Retrieved 30 April 2014.
^ "Ireland Constitution, Article 12(2.3)". International Constitutional Law. 1995. Retrieved 15 February 2008.
^ "Understanding the Limited Preferential Voting system – EMTV Online". 10 April 2017. Retrieved 18 February 2021.