Haydar (Arabic: حيدر), also spelt Hajdar, Hayder, Heidar, Haider, Heydar, Hyder, and other variants, is an Arabic male given name, also used as a surname, meaning "lion".
In Islamic tradition, the name is primarily associated with Ali ibn Abi Talib (first Shia Imam and fourth Rashidun Caliph), the son-in-law and cousin of Muhammad, who was nicknamed "Haydar".
[1] The variants Hyder and Hyderi (Urdu: حیدری) are Urdu variants used predominantly by Muslims in South Asia.
For people with these variant spellings, see: