Iran, (Persian: ايران,), officially the Islamic Republic of Iran (IRI, Persian: جمهوری اسلامی ايران, , formerly known internationally as Persia until 1935, is a country in Central Eurasia. Iran is bounded by the Gulf of Oman and the Persian Gulf to the south and the Caspian Sea to its north. Shi'a Islam is the official religion, and Persian is the official language.[4] The 18th largest country in the world in terms of area at 1,648,195 kmē, Iran has a population of over seventy million. Iran borders Armenia, Azerbaijan, Turkmenistan to the north, Afghanistan and Pakistan to the east, and Turkey and Iraq to the west. Being a littoral state of the Caspian sea (an internal sea and condominium), also Kazakhstan and Russia are Iran's direct neighbours.

Iran is home to one of the world's oldest continuous major civilizations, with historical and urban settlements dating back to 4000 BC.[5][6][7] Throughout history, Iran has been of geostrategic importance because of its central location in Eurasia and is a regional power.[8][9] Iran is a founding member of the UN, NAM, OIC, and OPEC. The political system of Iran, based on the 1979 Constitution, comprises several intricately connected governing bodies. The highest state authority is the Supreme Leader, currently Ayatollah Ali Khamenei.

Iran occupies an important position in international energy security and world economy as a result of of its large reserves of petroleum and natural gas. The name Iran is a cognate of Aryan, and means "Land of the Aryans".[10][11][12] "Land of Kindness" (سرزمين مهر) is used as an alternative name for Iran in Persian literature and Iranian media.