Château Thelian is the official residence of the President of the United Federation of Planets. Named after former President Thelianaresth th'Vorothishria, Château Thelian was built in the early 24th Century by Thelian to serve as his residence. Located in the Loire Valley, the Château has been the residence of every president since Thelian. Château Thelian is as large as the Château de Saint Brisson, also located in the valley, having been built to the specifications of many famous châteaux and containing many rooms.

Château Thelian's sitting room featured of wood-paneled walls and a large stone fireplace on the east wall, which was decorative only, sealed due to Federation safety regulation regarding open flames in government buildings. The west wall displayed portraits of all the Federation presidents since Thelian. The Château Thelian also had a dedicated transporter bay to allow quick access to the Palais de la Concorde. (ST novel: Articles of the Federation)

Château Thelian's status as the official residence of a head of government puts it in company with such structures as the White House, the Lodge, 24 Sussex Drive, the Palais de l'Élysée, and numerous other official residences.