Deirdre is the name of a tragic heroine in Irish mythology.

Deirdre may also refer to:

• Deirdre (given name), a list of people and fictional characters
• "Deirdre" (song), a song by the Beach Boys
• Deirdre (horse), a Thoroughbred racehorse
• Deirdre, a 1907 poem by W. B. Yeats
• LÉ Deirdre (P20), a ship in the Irish Naval Service
• Deirdre of the Sorrows, a 1909 play by J. M. Synge

• Dierdre (artist), world fusion artist Dierdre Dubois, former frontwoman of Ekova
• Deidre