Leopold I (name in full: Leopold Ignaz Joseph Balthasar Felician; Hungarian: I. Lipót) Habsburg (9 June 1640 – 5 May 1705), Holy Roman Emperor, King of Hungary, King of Bohemia, is the second son of the emperor Ferdinand III and his first wife Maria Ana of Austria.

His maternal grandparents are Philip III of Spain and Margaret of Austria.

He is also a first cousin of his rival, Louis XIV of France.

He became heir apparent on 9 July 1654 by the death of his elder brother Ferdinand IV, and reigns as Holy Roman Emperor from 1658 to 1705.

Leopold's reign is marked by military successes against the Ottoman Empire in the Great Turkish War through his greatest general Prince Eugene of Savoy, including at Saint Gotthard, Vienna, Second Mohács and Zenta.

By the end of the war, the Habsburg Monarchy has annexed Transylvania and much of Hungary.

Leopold is also known for his conflicts against France through the Nine Years' War and the War of Spanish Succession.

In the latter, he had hoped to enforce the Second Partition Treaty, which assigns the throne of the Kingdom of Spain to his son the Archduke Charles.

Leopold manages the war extremely well, and the Habsburg Monarchy scores decisive victories at Schellenberg and Blenheim.

His death in 1705 leaves the throne to his eldest son Joseph.