In Greek mythology, Alphesiboea (Ancient Greek: Ἀλφεσίβοια, romanized: Alphesíboia pronounced [alpʰesíboi̯a]), in some versions also called Arsinoë (Ancient Greek: Ἀρσινόη, romanized: Arsinóē pronounced [arsinóɛː]), is an Arcadian princess from the ancient Greek kingdom of Psophis, daughter of King Phegeus. Alphesiboea marries Alcmaeon after the murder of his mother, but he ends up deserting her for the love of another woman. Alcmaeon is then murdered by Alphesiboea's male relatives. Alphesiboea was one of the several owners of the necklace of Harmonia, a cursed artefact that brought ill fortune to its possessors.
Due to the great popularity of Alcmaeon's myth in antiquity, Alphesiboea is known to have appeared in many ancient dramatizations of the story, none of which are preserved today. At least three tragedies titled Alphesiboea are known to have been produced, alongside several Alcmaeons.