Dalibor is a Czech opera in three acts by Bedřich Smetana. The libretto was written in German by Josef Wenzig, and translated into Czech by Ervin Špindler. It was first performed at the New Town Theatre in Prague on 16 May 1868. The opera received criticism at the time for being overly influenced by German opera, including that of Richard Wagner.

The subject of the opera is Dalibor of Kozojed (fl. c. 1490), a Czech knight who took part in an uprising in Ploskovice in support of the oppressed people and was sentenced to death in 1498, during the reign of Vladislas II. The plot bears a resemblance to that of Ludwig van Beethoven's opera Fidelio, in that the central female characters in each opera disguise themselves in male clothing to try to save the hero.

Smetana had great affection for the opera, but because of the lukewarm reception, died thinking that he had failed with this opera. The revival in 1886, however, two years after the composer's death, was a success. In the 1890s, the opera received productions in Zagreb, Munich, and Hamburg. Gustav Mahler conducted an 1892 production in Vienna.