Tour T1 (also known as the Tour GDF Suez) is an office skyscraper in La Défense, the high-rise business district west of Paris, France.

Construction began in 2005 and the tower was completed and opened in 2008. The tower, 185 m (607 ft) tall, is the third-tallest skyscraper in La Défense after the Tour Total (190m) and Tour First (231m). Since 2010, the entirety of the building's office space has been rented by GDF Suez.

• Skyscraper
• La Défense
• List of tallest structures in Paris