Princess Marie Thérèse Louise of Savoy (8 September 1749 – 3 September 1792) was a member of the Savoy-Carignano cadet branch of the House of Savoy. She was married at the age of 17 to Louis Alexandre de Bourbon-Penthièvre, "Prince de Lamballe", the heir to the greatest fortune in France. After her marriage, which lasted a year, she went to court and became the confidante of Queen Marie Antoinette. She was killed in the massacres of September 1792 during the French Revolution.