Anna Komnene Doukaina (died 4 January 1286), known in French as Agnes, was Princess-consort of the Principality of Achaea in 1258–1278.
Anna was a daughter of the ruler of Epirus, Michael II Komnenos Doukas, and his wife, Theodora. In 1258, she was married to the Prince of Achaea, William II of Villehardouin, at Patras, while her sister Helena was married to Manfred of Hohenstaufen, King of Sicily. These marriages were part of a web of alliances directed against the Empire of Nicaea, whose expansion threatened both the interests of the Epirote ruler, who claimed the Byzantine imperial heritage for himself, and the very existence of the Latin states of Greece. The diplomatic and military manoeuvring that followed led to the eventual defeat of the Epirote–Latin alliance in the Battle of Pelagonia in 1259.
Anna, known as Agnes in French, was William's third wife. William was childless with his first two wives, but Anna bore him two daughters, Isabella and Margaret. After William II's death in 1278, as he had no sons, and per the Treaty of Viterbo, the princely title passed to the King of Sicily, Charles of Anjou. Anna inherited the Villehardouins' patrimonial domain, the Barony of Kalamata, and the fortress of Chlemoutsi, which she had received as a dowry from William. She also became guardian of her youngest daughter Margaret, while Isabella had been married to Charles' son Philip and had gone to Italy, where she remained even after her husband died in 1277.