Eudokia (or Eudocia) Ingerina (Greek: Ευδοκία Ιγγερίνα; c. 840 – c. 882) was a Byzantine empress as the wife of the Byzantine emperor Basil I, the mistress of his predecessor Michael III, and the mother of emperors Leo VI and Alexander, as well as the mother of Patriarch Stephen I of Constantinople.

Eudokia was the daughter of Inger, who was probably a Varangian, while her mother Melissena was a member of a prominent Greek family, the Martinakoi, who claimed imperial ancestry to Heraclius' sister and second mother-in-law,[citation needed] or according to a later alternative reconstruction by Christian Settipani, her connection to the Martinakoi came through her father, whom he identifies as a Byzantine noble, Inger Martinakios, logothete.

Around 855, Eudokia became the mistress of Theodora's son, Michael III, who thus incurred the anger of his mother and the powerful minister Theoktistos.

Unable to risk a major scandal by leaving his wife, Michael married Eudokia to his friend Basil but continued his relationship with her.

The strange promotion of Basil to co-emperor in May 866 lends support to the great probability that at least Leo was actually Michael III's illegitimate son.