Mitra is an Indian family name and surname found mostly amongst Bengali Hindus. The surname may have been derived either from the word mitra meaning friend or ally or from the name of an important deity in the Vedas.
Mitras belong to Kayastha caste in Bengal. The Bengali Kayasthas evolved as a caste from a category of officials or scribes, between the 5th/6th century CE and 11th/12th century CE, its component elements being putative Kshatriyas and mostly Brahmins. Mitras are considered as Kulin Kayasthas, along with Bose, Ghosh and Guha.