Yama or Yamaraa or jivayam is a Hindu and Buddhist deity of death, dharma, the south direction, and the underworld, belonging to an early stratum of Rigvedic Hindu deities. In Sanskrit, his name can be interpreted to mean "twin". He is also an important deity worshipped in Kalasha and now extinct Nuristani religions, indicating his prominence in ancient Hinduism.

In Hinduism, Yama is the son of sun-god Surya and Sandhya, the daughter of Vishwakarma. Yama is the brother of Shraddha Deva Manu and of his older sister Yami, which Horace Hayman Wilson indicates to mean the Yamuna. According to the Vedas, Yama is said to have been the first mortal who died. By virtue of precedence, he became the ruler of the departed, and is called "Lord of the Pits".

In Buddhism, Yama (Sanskrit: यम) is a dharmapala, a wrathful god or the Enlightened Protector of Buddhism that is considered worldly, said to judge the dead and preside over the Narakas ("Hell" or "Purgatory") and the cycle of rebirth.

The Buddhist Yama has, however, developed different myths and different functions from the Hindu deity. In Pali Canon Buddhist myths, Yama takes those who have mistreated elders, holy spirits, or their parents when they die. Contrary though, in the Majjhima Nikaya commentary by Buddhaghosa, Yama is a vimānapeta – a preta with occasional suffering.

In other parts of Buddhism, Yama's main duty is to watch over purgatorial aspects of Hell (the underworld), and has no relation to rebirth. His sole purpose is to maintain the relationships between spirits that pass through the ten courts, similar to Yama's representation in several Chinese religions.