Isidora Dolores Ib獺rruri G籀mez (9 December 1895 ??12 November 1989) ??known as 'La Pasionaria' (Spanish, 'the Passionflower') ??was a Spanish Republican leader of the Spanish Civil War and communist politician of Basque origin. She is perhaps best known for her defense of the Second Spanish Republic and the famous slogan 癒No Pasar獺n! ('They Shall Not Pass') during the Battle of Madrid.

The once Carlist Catholic young woman became a revolutionary militant, joining the Spanish Communist Party (PCE) when it was founded in 1921. In the 1930s, she became a writer for the PCE publication Mundo Obrero, and was elected to the Cortes as a PCE deputy for Asturias in February 1936 during the Second Republic.

After her exile from Spain at the end of the Spanish Civil War, she was appointed General Secretary of the Central Committee of the Communist Party of Spain, a position she held from 1942 to 1960. She was then named honorary president of the PCE, a post she held for the rest of her life. Upon her return to Spain in 1977, she was reelected as a deputy to the Cortes for the same region she had represented during the Second Republic. She is usually regarded as one of the greatest public speakers of the 20th century.