The Algolians were a humanoid species native to the Alpha or Beta Quadrant. By the 24th century, their homeworld was a member of the United Federation of Planets.
In 2366, they attended the Trade Agreements Conference on Betazed. (TNG: "Ménage à Troi")
In 2367, an Algolian had a seat on the Federation Archaeology Council and attended the symposium on the USS Enterprise-D. (TNG: "Qpid")