A Terrestrial planet is a planet, which is primarily composed of silicate rocks, or metals. In the Solar System the terrestrial planets are the inner planets closest to the Sun. The term 'Terrestrial planet' is derived from the Latin words for 'Earth' (Terra and Tellus), as these planets are, 'Earth-like'.

Terrestrial planets have a solid planetary surface, making them different from gas giants, which have no solid surface (although some gas giants do have a solid core.)