The Gran Telescopio Canarias (GTC) ("Great Telescope Canary Islands"), sometimes called Grantecan, is a 10.4m reflecting telescope being built at the Observatory of Roque de los Muchachos in the island of La Palma.

GTC will start observing in 2005. Its primary mirror is formed by 36 hexagonal segments fully controlled by an active optics control system. The GTC Project is a partnership formed by several institutions from Spain, Mexico and the University of Florida (USA) and an initiative from the Instituto de Astrofísica de Canarias (IAC).

Its Day One instruments are OSIRIS and CanariCam.