Maria Theresa of Naples and Sicily (6 June 1772 – 13 April 1807) was the eldest daughter of Ferdinand IV & III of Naples and Sicily (later Ferdinand I of the Two Sicilies) (1751–1825) and his wife, Marie Caroline of Austria (1752–1814). She was the last Holy Roman Empress and the first Empress of Austria.

Born Maria Teresa, and named after her maternal grandmother Maria Theresa of Austria, she was the eldest of 17 children born to her parents, the King and Queen of Naples and Sicily. Her father was a son of Charles III of Spain and Princess Maria Amalia of Saxony. Through her mother she was a niece of Marie Antoinette; through her father she was a niece of Maria Luisa of Spain and Charles IV of Spain. She was her mother's favourite child from birth until she left the Neapolitan court to marry.

Her brothers included the future King Francis and Leopold, Prince of Salerno. Another, Carlo, Duke of Calabria died in 1778 aged 3 of smallpox.

Her sisters included Grand Duchess of Tuscany. Her younger sister Princess Maria Cristina, was the wife of the future Charles Felix of Sardinia as Queen of Sardinia. Maria Cristina's twin Princess Maria Cristina Amelia died in 1783 of smallpox. Another sister was the Queen of the French as the wife of Louis Philippe I and the youngest was the future Princess of Asturias.

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