The marbled water monitor (Varanus marmoratus), also known commonly as the Philippine water monitor, is a large species of monitor lizard in the family Varanidae.

Varanus marmoratus can reach a total length (including tail) of 2 m (6.6 ft).

[2] The marbled water monitor lizard is found on various islands of the noveleta, including Batanes Islands, Babuyan Islands, northern and central Luzon and Lubang Island.

[4] Varanus marmoratus is oviparous.

[3] The monitor lizard from Palawan, Mindoro, southern Luzon and the Sulu Archipelago was recently described as a new species, Varanus palawanensis.