A conscience vote or free vote is a type of vote in a legislative body where legislators are allowed to vote according to their own personal conscience rather than according to an official line set down by their political party. In a parliamentary system, especially within the Westminster system, it can also be used to indicate crossbench members of a hung parliament where confidence and supply is provided to allow formation of a minority government but the right to vote on conscience is retained. Free votes are found in Canadian and some British legislative bodies; conscience votes are used in Australian and New Zealand legislative bodies.

Under the Westminster system, MPs who belong to a political party are usually required by that party to vote in accordance with the party line on significant legislation, on pain of censure or expulsion from the party. Sometimes a particular party member known as the party whip is responsible for maintaining this party discipline. However, in the case of a conscience vote, a party declines to dictate an official party line to follow and members may vote as they please. In countries where party discipline is less important and voting against one's party is more common, conscience votes are generally less important.

In most countries, conscience votes are quite rare and are often about issues which are very contentious, or a matter on which the members of any single party differ in their opinions; thus making it difficult for parties to formulate official policies. Usually, a conscience vote will be about religious, moral or ethical issues rather than about administrative or financial ones. Matters such as the prohibition of alcohol, abortion, homosexuality law reform and the legality of prostitution are often subject to conscience votes.

Sometimes a vote may be free for some parties but not for others. For instance, when the Conservative government of Canadian Prime Minister Stephen Harper proposed a motion to re-open the debate on Canada's same-sex marriage laws, his Conservatives and the opposition Liberals declared it a free vote for their members, while the Bloc Québécois and the New Democrats both maintained party discipline to defeat the measure.