Avery III was the third planet in the Avery system, located in the Vidiian Sodality in the Delta Quadrant. The planet was the site of a hidden underground Vidiian base, where Sulan conducted his research on the Phage.
In 2371, an away team from the USS Voyager, consisting of Lieutenants B'Elanna Torres, Tom Paris, and Peter Durst, were investigating magnesite deposits on Avery III when they were captured by the Vidiians. Durst was killed and his organs harvested before the team could be rescued. (VOY: "Faces")