Saint Stephen I (Hungarian: I.

(Szent) István; Latin: Sanctus Stephanus; Esztergom, Principality of Hungary, 967 or 969 or 975 – 15 August 1038, Esztergom or Székesfehérvár, Kingdom of Hungary), born as Vajk, is Grand Prince of the Hungarians (997–1000) and the first King of Hungary (1000–1038).

He greatly expands Hungarian control over the Carpathian Basin during his lifetime, broadly establishes Christianity in the region, and is generally regarded as the founder of the Kingdom of Hungary.

Pope Gregory VII canonized Stephen together with his son, Saint Emeric of Hungary, and Gerardo Sagredo, on 20 August 1083.

Stephen became one of the most popular saints in Hungary, and 20 August, which was also his feast day until 1687, is celebrated as a public holiday in Hungary commemorating the foundation of the state.