Lourinhanosaurus (meaning "Lourinhã lizard") was a genus of carnivorous theropod dinosaur that lived during the Late Jurassic Period (Kimmeridgian/Tithonian) in Portugal.

It is one of many large predators discovered at the Lourinhã Formation and probably competed with coeval Torvosaurus gurneyi, Allosaurus europaeus, and Ceratosaurus.

[2] Its type (and to date only) species is L. antunesi, in honour of Portuguese paleontologist Miguel Telles Antunes.

[2] A femur (ML 555) found at Porto das Barcas (Lourinhã Formation; Late Jurassic) has also been referred to L. antunesi.

Since the original description, some researchers have been favourable to the idea that L. antunesi is not even an allosauroid, but in fact a member of Megalosauroidea, a more basal group of tetanuran theropods.