Theresa Benedicta was the third child of Charles Albert, Elector of Bavaria and Holy Roman Emperor.

Her maternal grandparents were Joseph I, Holy Roman Emperor, and Wilhelmina Amalia of Brunswick-Lüneburg.

Her paternal grandparents were Maximilian II Emanuel, Elector of Bavaria, and Theresa Kunegunda Sobieska, the daughter of the King of Polish–Lithuanian Commonwealth, John III Sobieski.

Theresa Benedicta's siblings included her brother Maximilian III, Elector of Bavaria, and two sisters Maria Antonia, Electress of Saxony, and Maria Anna Josepha, Margravine of Baden-Baden.

She died on 29 March 1743 in Frankfurt at age 17 of either smallpox or chicken pox.