Heydar is a common male given name in Greater Iran, particularly in Iran and Azerbaijan. A variant of the Arabic name Haydar (also spelt Heidar, Haider, and other variants), it was a cognomen of Ali, who was known for his courage in battle.^{[citation needed]}

Heydar is sometimes transliterated as Gaidar or Geidar, from the Cyrillic spelling Гейдар.^{[citation needed]}

The name may refer to:

• Heydar Aliyev (1923–2003), Azerbaijani politician and president
• Heydar Babayev (born 1957), Azerbaijani politician
• Heydar Ghiai (1922–1985), Iranian architect
• Heydar Huseynov (1908–1950), Azerbaijani philosopher
• Heydar Moslehi (born 1957), Iranian politician
• Heydar Yaghma (1926–1986), Iranian poet

• Heydar Alat, Iran
• Heydar Babaya Salam, a work of poetry
• Heydar Baghi, Iran
• Heydar Didehban, Iran
• Heydar-e Posht-e Shahr, Iran
• Heydar Kar, Iran
• Heydar Kola, Iran
• Heydari (name), an Iranian surname