Kayastha or Kayasth denotes a cluster of disparate Indian communities broadly categorised by the regions of the Indian subcontinent in which they were traditionally located—the Chitraguptavanshi Kayasthas of North India, the Chandraseniya Kayastha Prabhus of Maharashtra, the Bengali Kayasthas of Bengal and Karanas of Odisha. All of them were traditionally considered "writing castes", who had historically served the ruling powers as administrators, ministers and record-keepers. The earliest known reference to the term Kayastha dates back to the Kushan Empire, when it evolved into a common name for a writer or scribe. In the Sanskrit literature and inscriptions, it was used to denote the holders of a particular category of offices in the government service. In this context, the term possibly derived from kaya- ('principal, capital, treasury') and -stha ('to stay') and perhaps originally stood for an officer of the royal treasury, or revenue department. Over the centuries, the occupational histories of Kayastha communities largely revolved around scribal services. However, these scribes did not simply take dictation but acted in the range of capacities better indicated by the term "secretary". They used their training in law, literature, court language, accounting, litigation and many other areas to fulfill responsibilities in all these venues. Kayasthas, along with Brahmins, had access to formal education as well as their own system of teaching administration, including accountancy, in the early-medieval India. Modern scholars list them among Indian communities that were traditionally described as "urban-oriented", "upper caste" and part of the "well-educated" pan-Indian elite, alongside Punjabi Khatris, Kashmiri Pandits, Parsis, Nagar Brahmins of Gujarat, Bengali Bhadraloks, Chitpawans and Chandraseniya Kayastha Prabhus (CKPs) of Maharashtra, South-Indian Brahmins including Deshastha Brahmins from Southern parts of India and upper echelons of the Muslim as well as Christian communities that made up the middle class at the time of Indian independence in 1947.

Chitraguptavanshi Kayastha, also referred to as North-Indian Kayastha, is a subgroup of Hindus of the Kayastha community that are mainly concentrated in the Hindi Belt of North India. In Hindu texts and traditions, they are described to have descended from the Hindu god Chitragupta who is usually depicted carrying "a flowing notebook, a pen and an inkpot" engaged in writing down human deeds. They are further divided into twelve Subgroups, each of which is claimed to be the progeny of Chitragupta's two consorts. The earliest recorded history of these groups goes to the early medieval period of Indian history, while the word "Kayastha" itself dates to the third-century CE. The North Indian Kayasthas were powerful components of the upper-bureaucracy and made highly influential urban elites under Hindu kings. They are mentioned in several Sanskrit literary, religious and epigraphical texts. Following Islamic invasions of India, they became some of the first Indian groups to learn Persian regularly and eventually became integrated into an Indo-Muslim governing community gaining hereditary control over the position of Qanungo (transl. "Registrar") but rarely converting to Islam. Under the colonial rule, many Kayastha families became early beneficiaries of the British power and success in the subcontinent. In 1919, Kayasthas accounted for two-thirds of all Indian Government law members across north India, with most of them in the United Provinces.

Kayastha is one of the social groups of India. They have a long history. They number around 30 million people and most of them live in India. Hindus believe that Lord Brahma created the world. He then created 16 sons from different parts of his body. His 17th son, Shree Chitraguptjee, was created from his mind and soul. He is the only son to be made from the whole body, not just parts. In human form he is called kayastha, kaya meaning whole. Kayastha's have two roles in the caste system, as Kshatriya (a warrior) and Brahmin (a learned person or scribe). The Kayastha caste is divided into 12 sub-castes. Subdivision of Kayastha:- Chitragupta Kayastha of North India, Prabhu Kayastha of Maharashtra, Karnam/Karuneegar (Kayastha) of South India, Karanas (Kayastha) of Orissa, Bengali Kayastha of Bengal and Kalitas (Kayastha) of Population approx 31 million.

The literary skills of the Kayastha people were in such demand that many of them moved to regions throughout India and Bangladesh. The Kayastha were originally administrators and bookkeepers for the kingdoms of northern India. In recent times the Kayastha have taken advantage of India's educational system and branched out into many professions that require a high degree of literacy. The primary languages of the Kayastha are Hindi and Bengali. They also speak the local languages of where they live and English. The Kayastha are well-known in India for being politicians, writers, philosophers, entertainers, and scientists. They are among the most successful and prominent castes in India and Bangladesh. The Kayastha live in cities and encourage their children to attend colleges and graduate schools. Parents and young people join together to find prospective marriage partners. Kayastha tend to marry within their group although some are marrying other higher caste persons. For many Kayastha their Hindu faith has become more cultural than religious. The large majority of the Kayastha practice Hinduism, the ancient religion of the Indian subcontinent. According to tradition the Kayastha were created by Brahmin to help the god of death Dharamraj keep records of good and bad deeds. They worship and serve the gods of the Hindu pantheon. Hindus believe that by performing rituals and good works that they will attain moksha or freedom from the endless cycle of birth, death and rebirth. The Kayastha visit Hindu temples and offer prayers, food, flowers, and incense to their gods in hopes of gaining protection and benefits. They do not have a personal or familial relationship with their gods. There are many forms of Hinduism, each with its own deities and beliefs. The main yearly holidays of the Kayastha people are Holi, the festival of colors and the start of spring, Diwali, the festival of lights, Navratri, the celebration of autumn and Rama Navami, Rama's birthday. The caste system divides Hindus into four main categories. The lowest communities are outside of the caste system. The Kayastha fit into the Kshatriya and Vaishyas castes. Both have good status in Hindu society.

Kayastha or Kayasth denotes a cluster of disparate Indian communities broadly categorised by the regions of the Indian subcontinent in which they were traditionally located—the Chitraguptavanshi Kayasthas of North India, the Chandraseniya Kayastha Prabhus of Maharashtra, the Bengali Kayasthas of Bengal and Karanas of Odisha. All of them were traditionally considered "writing castes", who had historically served the ruling powers as administrators, ministers and record-keepers. The earliest known reference to the term Kayastha dates back to the Kushan Empire,when it evolved into a common name for a writer or scribe. In the Sanskrit literature and inscriptions, it was used to denote the holders of a particular category of offices in the government service. In this context, the term possibly derived from kaya- ('principal, capital, treasury') and -stha ('to stay') and perhaps originally stood for an officer of the royal treasury, or revenue department.Over the centuries, the occupational histories of Kayastha communities largely revolved around scribal services. However, these scribes did not simply take dictation but acted in the range of capacities better indicated by the term "secretary". They used their training in law, literature, court language, accounting, litigation and many other areas to fulfill responsibilities in all these venues.Kayasthas, along with Brahmins, had access to formal education as well as their own system of teaching administration, including accountancy, in the early-medieval India.Modern scholars list them among Indian communities that were traditionally described as "urban-oriented", "upper caste" and part of the "well-educated" pan-Indian elite, alongside Punjabi Khatris, Kashmiri Pandits, Parsis, Nagar Brahmins of Gujarat, Bengali Bhadraloks, Chitpawans and Chandraseniya Kayastha Prabhus (CKPs) of Maharashtra, South-Indian Brahmins including Deshastha Brahmins from Southern parts of India and upper echelons of the Muslim as well as Christian communities that made up the middle class at the time of Indian independence in 1947.

Bengali Kayastha (Bengali: বাঙালি কায়স্থ) is a Bengali Hindu caste originated from the Bengal region of Indian subcontinent, and is one of the main subgroups of the Kayastha community. The historical caste occupation of Kayasthas throughout India has been that of scribes, administrators, ministers and record-keepers; the Kayasthas in Bengal, along with Brahmins and Baidyas, are regarded among the three traditional higher caste that comprise the "upper layer of Hindu society". During the British Raj, the Bhadraloks of Bengal were drawn primarily, but not exclusively, from these three castes, who continue to maintain a collective hegemony in West Bengal. The social and religious patterns of Bengal had historically been distinctively different from those in the orthodox Hindu heartland of North India and this impacted on how the caste system developed there. Bengal, being located east of the traditional Aryavarta (Aryan) region between the Ganges and Yamuna rivers, remained insulated from the full impact of Brahminical orthodoxy for many centuries. The influence of Buddhism remained strong there, continuing under the Buddhist rulers of the Pala dynasty from the eighth through the eleventh century CE. During the Gupta period, Kayastha had not crystallised into a caste, and represented a professional group. Kayasthas frequently appear in the Gupta inscriptions mostly as professional writers or scribes. The importance of the lekhaka or writer seems to have increased during the Gupta period; the term 'Kayastha' was a part of the Gupta administrative terminology. A number of inscriptions during this period mention the office of Prathama-Kayastha, meaning chief scribe in the administrative office, and represented "probably the Chief Secretary to the administrative Board".

In early twentieth-century legal settlements over inheritance disputes in Calcutta, Kayasthas, a socio-ethnic group formerly considered upper caste, came to be identified as Shudras, the lowest of the four castes. These inheritance settlements, taking place at the Calcutta High Court, deployed caste as a legal category to determine the lawful transfer of property between claimants. Both British and Indian judges, working within a colonial legal framework, relied heavily on caste-based ritual practices to resolve inheritance disputes. Their verdicts reshuffled caste identities while reinforcing existing hierarchies: the formerly upper-caste Bengali Kayasthas were relegated to the lowest level of Shudras on the caste pyramid. Bengali Kayasthas, naturally, resisted this imposed status. They formed caste associations in which their activism fuelled a distinct brand of Kayastha caste pride. At the same time, however, they also internalized colonial definitions of their group to reconfigure their identity and challenged both the colonial state and Brahmin hegemony. Investigating essays published in the monthly periodical Kayastha Patrika (1902–1926), I will argue that inheritance settlements carved out a distinct socio-legal space where both the British and Bengali Kayasthas invented, exploited, renewed, and legitimized caste hierarchies to craft a new self-identity.

Kayasthas are said to be descendants of Chitragupta, the deity responsible for recording sins or merits of every living being. Kayasthas are usually referred as the scribe class. Their varna however is very disputed. In Bengal however, Kayasthas are said to be separate to of Brahmins as Bengali Brahmins do not consider themselves as Kayasthas. Nevertheless, even this is disputed. So which varna do Kayasthas especially Bengali ones belong to? The Kayasth trace their genealogy from Adi Purush Shri Chitraguptaji Maharaj. It is said that after Lord Brahma had created the four Varnas (Brahmins, Kshatriyas, Vaishyas and Shudras), Yama snonym Dharamraj requested Lord Brahma to help him record the deeds, good and evil, of men, and administer justice. Lord Brahma went into meditation for 11000 years and when he opened his eyes he saw a man holding pen and ink-pot in his hands and a sword girdled to his waist. Lord Brahma spoke: Thou hast been created from my body (Kaya), therefore shall thy progeny be known as the Kayasthas. Thou hast been conceived in my mind (Chitra) and in secrecy (gupta), thy name shall also be Chitragupta. Brahma then enjoined him to dispense justice and punish those who violated the dharma.

The Muslim Kayastha (Urdu: مسلمان کائستھ), also known as Siddiqui, are a community of Muslims, are related to the Kayastha of northern India, mainly modern Uttar Pradesh, who converted to Islam during the rule of the Islamic empires in India. The Kayastha community has historically converted to Islam and held the occupations of land record keeping, administration and accounting. They speak Urdu, although they are also fluent in Hindi in India. In Pakistan they also speak Sindhi and Punjabi. They consider themselves part of the Shaikh community, and claim to be the descendants of Abu Bakr, the first Sunni Caliph, who was a companion of and the father-in-law of Muhammad. The Muslim dynasties recruited individuals from different Hindu castes by merit and trained them to become civil servants and members of the Kayasth caste. They successfully adapted as scribes and functionaries under Islamic rule, then the British. In the reign of the Mughals, a number of educated upper caste Hindus with sharp intellects attained administrative positions through rapid adaptation to the Persian language and culture of these new rulers of South Asia. These influential upper caste Hindus formed the Kayastha, whose secular viewpoint and adaptability allowed them to succeed. Their close association with Muslim rulers led most of them to convert to Islam. Most South Asian kingdoms and princely states valued Kayasthas as desired citizens or immigrants in the second millennium. They treated the Kayasthas more as a community than a Hindu caste, because they developed expertise in Persian (the state language in Islamic India), and learned Turkish and Arabic, economics, administration and taxation. This gave them an edge over the Brahmins, the priestly Hindu caste) who traditionally reserved the study of Sanskrit shastras for themselves. Muslim Kayastha outnumber the Hindu Kayastha even today. They adapted to change, such as the advent of the British Raj. They learned English, and the more affluent sent their children to school in the United Kingdom. They became civil servants, tax officers, junior administrators, teachers, legal helpers and barristers, and rose to the highest positions accessible to natives in British India.