The Tandar sector was a sector of space and home to Tandar Prime. The Enterprise once visited the Tandar sector. While there, the crew discovered that a great many Suliban had moved to the sector after their homeworld become uninhabitable. (ENT episode: "Detained") Department of Temporal Investigations special agents Gariff Lucsly and Marion Dulmur visited the Tandar sector in 2381 in order to investigate a temporal incident related to Professor Vard. (DTI novel: Watching the Clock)