Star Trek Online, often abbreviated as STO, is a massively multiplayer online role-playing game (MMORPG) developed by Cryptic Studios based on the popular Star Trek series created by Gene Roddenberry. The game is set in the 25th century, 30 years after the events of Star Trek Nemesis.Star Trek Online is the first massively multiplayer online role-playing game within the Star Trek franchise and was released on February 2, 2010. The game used to require a game purchase and a recurring monthly fee. On January 17, 2012 it adopted the free-to-play model.

Each player is the captain of their own individual ship. The game setting is in a war-time universe in the year 2409, utilizing any and all officers who have access to a ship, including the player's character. In keeping with naval tradition, anyone who commands a ship, regardless of his or her actual rank, is considered a de-facto "captain". Players can start in Star Trek initially in only one faction as a Federation Captain, but other factions unlock as players level up. Currently the only two factions available are Federation (at the start) and Klingon (upon reaching Level 25). Each ship has a number of crewmen who will all be NPCs, referred to as Bridge Officers. Bridge Officers have a separate progression, including the purchase of skills and equipment, and can be promoted to higher ranks by their ship's captain.

Star Trek is an American science fiction entertainment franchise created by Gene Roddenberry. The core of Star Trek is its six television series: The Original Series, The Animated Series, The Next Generation, Deep Space Nine, Voyager, and Enterprise. The franchise also includes eleven feature films, dozens of games, hundreds of novels, numerous toy lines and replicas, as well as a themed attraction in Las Vegas (opened in 1998 and closed in September 2008) and at least two traveling museum exhibits of props. Beginning with the original television series and continuing with the subsequent films and series, the franchise has become a cult phenomenon, initiated the creation of the full-fledged language Klingon, and spawned many pop culture references.