Theyyam (Malayalam: തെയ്യം) or Theyyattam or Thira is a popular Hindu ritual form of worship of North Malabar in Kerala state, India, predominant in the Kolathunadu area (consisting of present-day Kasargod, Kannur Districts, Mananthavady Taluk of Wayanad and Vadakara & Koyilandy Taluks of Kozhikode of Kerala state. As a living cult with several thousand-year-old traditions, rituals and customs, it embraces almost all the castes and classes of the Hindu religion in this region. The performers of Theyyam belong to the indigenous tribal community, and have an important position in Theyyam. This is unique, since only in Kerala, do both the upper-caste Brahmins and lower-caste tribals share an important position in a major form of worship. The term Theyyam is a corrupt form of Devam or God. People of these districts consider Theyyam itself as a God and they seek blessings from this Theyyam. A similar custom is followed in the Tulu Nadu region of neighbouring Karnataka known as Bhuta Kola
According to the legendary Keralolpathi, Parasurama sanctioned festivals like Kaliyattam, Puravela and Daivattam or Theyyattam to the people of the North Malabar region. He also assigned the responsibility of performing the Theyyam dance to the indigenous tribal communities like Malayar, Panan, Vannan and Velan. “There can be no doubt”, say Bridget and Raymond Alchin, “that a very large part of this modern folk religion is extremely ancient and contains traits which originated ruing the earliest periods of Neolithic, Chalcolithic settlement and expression” (The Birth of Indian Civilization 1968 p. 3039, and indeed, Theyyam is representative of a form of Hinduism (albeit non-Brahminical) having been practised by tribal communities since time immemorial. This form of worship, often involving liquor and meat as offerings to Bhagawathi, Shiva, Vishnu, co-existed with the Sattvic rituals practised by Nambudiri Brahmins in temples. In fact, Theyyam was nearly always sponsored by members of the ruling class, such as Nair feudal chiefs, and achieved much prominence, therefore Theyyam festivals and Temple festivals were celebrated with equal vigour. Theyyam is an art form of the Dravidians. And it has a revolutionary concept behind it since the Theyyam artists are from low-caste communities such as Malayan or Vanaan. Even the high-caste people will have to worship the Gods come in the form of Theyyam, so we can say it was against the then caste-system in Kerala.