Deshastha Brahmin is a Hindu Brahmin subcaste mainly from the Indian state of Maharashtra and North Karnataka. Other than these states, according to authors K. S. Singh, Gregory Naik and Pran Nath Chopra, Deshastha Brahmins are also concentrated in the states of Telangana (which was earlier part of Hyderabad State and Berar Division), Andhra Pradesh and Madhya Pradesh (which was earlier part of Central Provinces and Berar) Historian Pran Nath Chopra and journalist Pritish Nandy say, "Most of the well-known saints from Maharashtra, Karnataka and Andhra Pradesh were Deshastha Brahmins". The mother tongue of Deshastha Brahmins is either Marathi or Kannada.

Over the millennia, the Deshastha community has produced mathematicians such as Bhāskara II, Sanskrit scholars such as Bhavabhuti, Satyanatha Tirtha, Satyadharma Tirtha; Bhakti saints such as Dnyaneshwar, Eknath, Purandara Dasa, Samarth Ramdas and Vijaya Dasa; polemical logician such as Jayatirtha and non-polemical scholar such as Raghuttama Tirtha.

The traditional occupation of Deshastha Brahmins is priesthood and the Kulkarni Vatan (village accountants). They also pursued secular professions such as writers, accountants, moneylenders and also practised agriculture. In historic times a large number of Deshasthas held many prominent positions such as Peshwa, Diwan, Deshpande (district accountants), Deshmukh, Patil, Gadkari, Desai, and Nirkhee (who fixed weekly prices of grains during the Nizam's Rule). Authors Vora and Glushkova state that "Deshastha Brahmins have occupied a core place in Maharashtrian politics, society and culture from almost the beginning of the Maharashtra's recorded history. Occupying high offices in the state and even other offices at various levels of administration, they were recipients of state honours and more importantly, land grants of various types."

The word Deshastha derives from the Sanskrit deśa (inland, country) and stha (resident), literally translating to "residents of the country". The valleys of the Krishna and the Godavari rivers, and a part of Deccan plateau adjacent to the Western Ghats, are collectively termed the Desha – the original home of the Deshastha Brahmins.

In Tamil Nadu, Deshastha Brahmins are also referred as Rayar Brahmins. The word Rayar means king in South India.

Deshastha Brahmins fall under the Pancha Dravida Brahmin classification of the Brahmin community in India. Along with the Karhade and Konkanastha Brahmins, the Marathi-speaking Deshastha Brahmins are referred to as Maharashtrian Brahmins, which denotes those Brahmin subcastes of the Deccan Plateau which have a regional significance in Maharashtra, while the Kannada-speaking Deshastha Brahmins from the Deccan Plateau region of Karnataka are referred to as Karnataka Brahmins or Carnatic Brahmins.

Deshastha Brahmins are further classified in two major sub-sects, the Deshastha Rigvedi and the Deshastha Yajurvedi, who earlier used to inter-dine but not inter-marry but now intermarriages between the two sub-groups is common. These sub-sects are based on the Veda they follow.

The Deshastha Rigvedi Brahmins (DRB) are followers of Rigveda and follow Rigvedic rituals. Deshastha Rigvedi Brahmins are followers of Ashvalayana sutra and Shakala Shakha of Rigveda. Deshastha Rigvedi Brahmins are the most ancient sub-caste among Deshasthas and are found throughout the Deccan. According to Iravati Karve, Deshastha Rigvedi Brahmins are found in western and central Deccan along the banks of the Godavari and the Krishna rivers and are spread deep into Karnataka. Deshastha Rigvedi Brahmins are endogamous group which include families from difference linguistic regions. Deshastha Rigvedi Brahmins include some families that speak Marathi and some speak Kannada, majority of marriages happen within the families of same language but the marriages between Marathi and Kannada speaking families do happen often.