Cārvāka (Sanskrit: चार्वाक), also known as Lokāyata, is a system of Indian philosophy that assumes various forms of philosophical skepticism and religious indifference. It seems named after Cārvāka, the probable author of the Bārhaspatya-sūtras and probably a follower of Brihaspati, who founded the Lokāyata philosophy.

In overviews of Indian philosophy, Cārvāka is classified as a heterodox (nāstika) system, the same classification as is given to Buddhism and Jainism. It is characterized as a materialistic and atheistic school of thought. While this branch of Indian philosophy is not considered to be part of the six orthodox schools of Hindu philosophy, some describe evidence of a materialistic movement within Hinduism.

The name Lokāyata can be traced to Kautilya's Arthashastra, which refers to three ānvīkṣikīs (logical philosophies), Yoga, Samkhya and Lokāyata. Lokāyata here still refers to logical debate (disputatio, "criticism") in general and not to a materialist doctrine in particular. Similarly, Saddaniti and Buddhaghosa in the 5th century connect the "Lokāyata" with the Vitandas (sophists).