Archduchess Isabella Clara of Austria, Austrian archduchess (d. 1685)
Isabella Clara of Austria (12 August 1629 – 24 February 1685), was a Duchess consort of Mantua, Montferrat, Nevers (until 1659), Mayenne (until 1654) and Rethel (until 1659) by marriage to Charles II, Duke of Mantua and Montferrat.

During 1665–1671 she was Regent of the Duchies of Mantua and Montferrat on behalf of her minor son. Accused of marrying her lover without Imperial consent, she was forced to take the veil as a nun and imprisoned at the Ursuline monastery of Mantua until her death.