Emir, sometimes transliterated amir, amier, or ameer, is a word of Arabic origin that can refer to a male monarch, aristocrat, holder of high-ranking military or political office, or other person possessing actual or ceremonial authority. The title has a long history of use in the Arab World, East Africa, West Africa, Central Asia, and the Indian subcontinent. In the modern era, when used as a formal monarchical title, it is roughly synonymous with "prince", applicable both to a son of a hereditary monarch, and to a reigning monarch of a sovereign principality, namely an emirate. The feminine form is emira, with the same meaning as "princess". Prior to its use as a monarchical title, the term "emir" was historically used to denote a "commander", "general", or "leader". In contemporary usage, "emir" is also sometimes used as either an honorary or formal title for the head of an Islamic, or Arab organisation or movement.

अमीर या हम्मीर (संस्कृत) का अर्थ सेनापति या राज्यपाल या सूबेदार होता है। इसी नाम से भारत में इस्लामी साम्राज्य के प्रमुख पद-धारकों को भी द्योतित किया जाता था। समय के साथ भारतीय उपमहाद्वीप में इसका अर्थ 'धनवान' हो गया।