Y'Lira Medoxa was a female Selenean Starfleet officer in the late 24th century.

In 2367, Medoxa was part of an away team that discovered the Protean Codex. Only Medoxa and two others, Jadzia Dax and Axael Krinn, from the team of five survived the encounter. However, Medoxa was permanently maimed, her brain losing one of its five lobes. She was left without the ability to dream or procreate and was considered a ghost among her people.

In 2375, Captain Medoxa was the commanding officer of the Federation starship USS Anansi. (DS9 short story: "Chiaroscuro")