Maria Feodorovna Nagaya (Russian: Мария Фёдоровна Нагая) (died 1608) was a Russian tsaritsa and eighth (uncanonical) wife of Ivan the Terrible.
Maria married Ivan IV in 1581 and a year later gave birth to their son Dmitry. After the Tsar's death in 1584, Nagaya, her son and her brothers were sent into exile to Uglich by Boris Godunov, where she lived until the mysterious death of tsarevich Dmitry in 1591. Maria and her relatives were accused of "criminal negligence" and, as a result, her brothers were incarcerated and she was made a nun in a monastery. In 1605, after the accession of False Dmitriy I in Moscow, Nagaya was forced to "recognize" him as her son and returned to Moscow. All of her family members were freed, reinstated in their ranks and given their confiscated property. After the death of False Dmitriy I in 1606, Maria Nagaya renounced him as her son.