孔多塞制（Condorcet voting），或称双序制，是由法国数学家与政治家孔多塞以孔多塞准则衍生的投票制度。投票者将候选人或候选的项目随自己的喜好而排名，例如第一意愿写「1」，第二意愿写「2」，如此类推。这种方法将每个选项与所有其他的选项成对比较，一次一个，而击败所有其他选项的选项便是赢家。只要一个选项在大多数选票上的位置高于另一个选项，那么它便击败了那个选项。

这些方法通常被称为孔多塞制，因为孔多塞准则确保了它们在大多数选举中都能获得一样的结果，也就是存在着一个孔多塞赢家。不同孔多塞制之间的差别在于出现没有选项被击败时的情况，意味着产生了一个选项之间不断击败对方的循环，这被称为孔多塞悖论。为了解决孔多塞悖论的循环，当没有孔多塞赢家出现而选择特定孔多塞版本来决定赢家的状况被称为孔多塞完结法。

A Condorcet method (English pronunciation: /kɒndɔːrˈseɪ/) is any election method that elects the candidate that would win by majority rule in all pairings against the other candidates, whenever one of the candidates has that property. A candidate with that property is called a Condorcet winner (named for the 18th-century French mathematician and philosopher Marie Jean Antoine Nicolas Caritat, the Marquis de Condorcet, who championed such outcomes). A Condorcet winner doesn't always exist because majority preferences can be like rock-paper-scissors: for each candidate, there can be another that is preferred by some majority (this is known as Condorcet paradox).