The Moscow Kremlin (Russian: Моско́вский Кремль, tr. Moskovskiy Kreml; IPA: [mɐˈskofskʲɪj krʲemlʲ]), sometimes referred to as simply the Kremlin, is a historic fortified complex at the heart of Moscow, overlooking the Moskva River (to the South), Saint Basil's Cathedral and Red Square (to the East) and the Alexander Garden (to the West). It is the best known of kremlins (Russian citadels) and includes five palaces, four cathedrals and the enclosing Kremlin Wall with Kremlin towers. The complex serves as the official residence of the President of the Russian Federation.

The name Kremlin means "fortress", and is often used as a metonym to refer to the government of the Soviet Union (1922–1991) and its highest members (such as general secretaries, premiers, presidents, ministers, and commissars), in the same way that the metonym Élysée Palace refers to the President of the French Republic, the White House refers to the Executive Office of the President of the United States and Number 10 Downing Street or Whitehall refers to the Offices of Prime Minister of the United Kingdom and the British Government. It is still used in reference to the government of the Russian Federation and even the Russian President's official website is Kremlin.ru. "Kremlinology" refers to the study of Soviet and Russian policies.