Iyer (also spelt as Ayyar, Aiyar, Ayer or Aiyer) is a caste of Hindu Brahmin communities of Tamil origin. Most Iyers are followers of the Advaita philosophy propounded by Adi Shankara. The majority reside in Tamil Nadu, India.
Iyers are sub-divided into various sub-sects based on cultural and regional differences. Like all Brahmins, they are also classified based on their gotra, or patrilineal descent, and the Veda they follow.
Iyers fall under the Pancha Dravida Brahmin sub-classification of India’s Brahmin community and share many customs and traditions with other Brahmins. In recent times, they have felt affected by reservation policies and the Self-Respect Movement in the Indian state of Tamil Nadu. This has helped encourage a large migration to other parts of India and the English-speaking world.
Apart from the prevalent practice of using the title “Iyer” as surname, Iyers also use other surnames, such as Sāstri or Bhattar.