An uncontested election is an election in which the winning candidate did not face a serious challenger. This often entails the number of candidates being the same as or fewer than the number of places available for election, meaning that all candidates are guaranteed to be elected unless there are provisions provided for this. For example, in some election systems, absence of opposing candidates may not guarantee victory; possible factors are a quorum or minimum voter turnout; a none of the above option (effectively turning the election into a referendum on the candidate's election); or the availability of write-in candidates on the ballot. In some uncontested elections, the normal process of voters casting ballots and election official counting votes is cancelled as superfluous and costly; in other cases the election proceeds as a formality.

In liberal democracies, uncontested elections are a cause for concern because many understandings of democracy, such as that of Robert Dahl, rely on the idea of voters choosing among alternatives.

Running without opponents is not always a guarantee of winning.

Many elections require that the winner has not only the most votes of all candidates, but also either a minimum number of votes or minimum fraction of votes cast, which may apply if many voters cast blank votes or spoiled votes. If elections require a minimum voter turnout, then abstention may likewise invalidate the election and trigger a fresh election. Some elections allow a "none of the above" option for the same purpose, and some allow voters to add write-in candidates to the ballot, so the pre-printed candidate is not truly uncontested.

In the Philippines, the sole candidate in an uncontested election must have at least one vote in order to win the seat; an exception is on special elections, where the sole candidate is deemed elected, and the election is no longer held.

This is also true in general elections in the United States. There are cases in local government races where the sole candidate on the ballot finished with zero votes and thus have lost an uncontested election; this is because almost all U.S. government seats require candidates to reside in the municipality they seek to represent, and means the candidates themselves must, usually out of forgetfulness or lack of time on election day, fail to vote for themselves. In such cases, the other members of the body usually appoint someone to the vacant seat.

This does not apply in primary elections: if only one candidate qualifies for a party's nomination, the primary is scratched and the candidate is declared nominated.

In liberal democracies like the United States, strong support for one candidate have resulted in uncontested elections. In the United States presidential elections of 1788-1789 and 1792, George Washington ran uncontested for President, though in the latter election the ballot for the Vice President was contested by both Federalists and Democratic-Republicans. In the 1820 election, James Monroe also ran unopposed, though New Hampshire elector William Plumer cast a vote for John Quincy Adams as a symbolic measure.