Adolf Frederick, or Adolph Frederick was King of Sweden from 1751 until his death in 1771. He was the son of Christian August of Holstein-Gottorp, Prince of Eutin, and Albertina Frederica of Baden-Durlach. He was an uncle of Catherine the Great and husband to Louisa Ulrika of Prussia.

Christian August of Holstein-Gottorp-Eutin was a cadet of the reigning ducal House of Holstein-Gottorp who became prince of Eutin, prince-bishop of Lübeck and regent of the Duchy of Holstein-Gottorp.