The fourth season of the American science fiction television series Star Trek: Voyager commenced airing on UPN in the United States on September 3, 1997, and concluded on May 20, 1998, after airing 26 episodes. Set in the 24th century, the series followed the adventures of the Starfleet and Maquis crew of the starship USS Voyager after they were stranded in the Delta Quadrant, far from the rest of the Federation. Series four featured the debut of new main cast member Jeri Ryan as Seven of Nine, nicknamed Seven, and the departure of Jennifer Lien, who portrayed Kes during the first three seasons of the show.