Heydar (Azerbaijani Heydər) is an Azerbaijani given name. It is sometimes transliterated as Gaidar or Geidar, from the Cyrillic spelling Гейдар. Notable people named Heydar include:
- Heydar Aliyev (1923–2003), President of Azerbaijan
- Heydar Babaya Salam, Azerbaijani-Iranian writer
Heydar is also an alternative transliteration for the Arabic name Haydar (Arabic حيدر ).