Adelaide of Austria (Adelheid Franziska Marie Rainera Elisabeth Clotilde; 3 June 1822 – 20 January 1855) was the Queen of Sardinia by marriage to Victor Emmanuel II of Sardinia, future King of Italy, from 1849 until 1855 when she died as a result of childbirth. She was the mother of Umberto I of Italy.

She was born at the Royal Palace of Milan to Rainer Joseph of Austria and his wife Elisabeth of Savoy. Named Adelaide, or known as Adele in the family, she held the title of Archduchess of Austria. Her father was the Viceroy of Lombardy-Venetia and was a son of Leopold II, Holy Roman Emperor and Maria Luisa of Spain. Her mother was a member of the House of Savoy and a daughter of the Prince of Carignano, the head of the junior branch of the House of Savoy who ruled the Kingdom of Sardinia. Her younger brother Archduke Rainer Ferdinand later acted as Minister President of Austria. Both of her brothers contracted morganatic marriages.

On 12 April 1842, at the Palazzina di caccia di Stupinigi, she married Victor Emmanuel of Savoy. The marriage was used to cement relations between the House of Savoy and that of the House of Habsburg but was viewed by many people of the time to increase Austrian power in Italy.