Tharosaurus (meaning "Thar Desert lizard") is an extinct genus of dicraeosaurid sauropod dinosaur from the Middle Jurassic Jaisalmer Formation of India.

The generic name, "Tharosaurus", combines a reference to the Thar Desert where the holotype was found with the Greek word "sauros", meaning "lizard".

[1] Bajpai et al. (2023) recovered Tharosaurus as an early-diverging dicraeosaurid, suggesting it represents a relic of a lineage that evolved in India and later spread across the world.

The results of their phylogenetic analyses are shown in the cladogram below:[1] Suuwassea Lingwulong Bajadasaurus Tharosaurus Pilmatueia Brachytrachelopan The Jaisalmer Formation represents a deposit on the Tethyan coast of India.

Other dinosaurs from this environment include a large theropod and a turiasaurian sauropod both known only from teeth,[3][4] along with a possible spinosaurid known only from a toe claw.