Ahir or Aheer are a community of traditionally non-elite pastoralists in India, most members of which identify as being of the Indian Yadav community because they consider the two terms to be synonymous. The Ahirs are variously described as a caste, a clan, a community, a race and a tribe.
The traditional occupations of Ahirs are cattle-herding and agriculture. Since late 19th century to early 20th century, Ahirs have adopted Yadav word for their community and have claimed descent from the mythological king Yadu as a part of a movement of social and political resurgence through Sanskritisation process under the influence of Arya Samaj.
Ahirs in India are known by numerous other names, including Gauli and Ghosi or Gop in North India. In Gujarat and South India as Ayar, Golla and Konar. Some in the Bundelkhand region of Uttar Pradesh are known as Dauwa. The Ahirs have more than 20 sub-castes.
Ahirs are found throughout India but are particularly concentrated in the northern area. Apart from India, Ahirs have significant population in Nepal, Mauritius, Fiji, South Africa and the Caribbean especially Guyana, Trinidad and Tobago, and Suriname. In Mauritius and Caribbean they are mostly the descendants of settlers who arrived between the 19th and 20th centuries from the former pre-partitioned sub-continent of India during the time of the British Raj.
Gaṅga Ram Garg considers the Ahir to be a tribe descended from the ancient Abhira community, whose precise location in India is the subject of various theories based mostly on interpretations of old texts such as the Mahabharata and the writings of Ptolemy. He believes the word Ahir to be the Prakrit form of a Sanskrit word, Abhira, and he notes that the present term in the Bengali and Marathi languages is Abhir.
Garg distinguishes a Brahmin community who use the Abhira name and are found in the present-day states of Maharashtra and Gujarat. That usage, he says, is because that division of Brahmins were priests to the ancient Abhira tribe.