The Galileo National Telescope, (Italian: Telescopio Nazionale Galileo; TNG; code: Z19) is a 3.58-meter Italian telescope, located at the Roque de los Muchachos Observatory on the island of La Palma in the Canary Islands, Spain.

The telescope saw first light in 1998 and is named after the Italian Renaissance astronomer Galileo Galilei.

The TNG is an altazimuthal reflecting telescope with a Ritchey-Chretien optical configuration and a flat tertiary mirror feeding two opposite Nasmyth foci.

The interface between the telescope fork and the instruments at both Nasmyth foci is provided by two rotator/adapters.

This guarantees flexibility during an observing session, since it is possible to change instrument during the night with a loss of time limited to a few minutes.