Archduke Stefan of Austria, Prince of Tuscany (German: Stefan, Erzherzog von Österreich, Prinz von Toskana) (15 August 1932, Mödling, Lower Austria, Austria – 12 November 1998, Brighton, Michigan, United States) was a member of the House of Habsburg an Archduke and Prince of Tuscany by birth. Stefan was the eldest child and son of Archduke Anton of Austria and his wife Princess Ileana of Romania.

Stefan was baptised with the name of Stefan von Habsburg-Lothringen. He was born in Mödling, Austria and spent the first years of his childhood in Castle Sonnberg, Austria. In 1942, he moved with his parents and four sisters and brother to Romania. While there, Stefan's parents made their residence at Bran, Braşov. After his 1st cousin, Michael of Romania,was forced to abdicate and expelled by the Communist late in 1947, Stefan left the country with his parents. Stefan then lived first in Switzerland, then in Argentina, and then finally in the United States. He was naturalized as a United States citizen. He was a graduate from Malvern Preparatory School and MIT. He established a division for advanced research at General Motors in Detroit, Michigan.

Stefan married morganatically to Mary Jerrine Soper (born 19 June 1931 in Boston, daughter of Charles B. Soper and wife Agnes McNeil; died 14 July 2015 in Farmington Hills, MI) on 26 August 1954 at St. Elizabeth's Church in Milton, Massachusetts. Stefan and Jerrine had five children together:

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