Hinduism is the dominant religion practised in the state of Assam. According to some scholars, it is home to some of the most complex and poorly understood traditions in Hinduism. People follow traditions belonging to Shaivism, Shaktism, Tantra, and an indigenous form of Vaishnavism called Ekasarana Dharma; taken together the practitioners constitute around 61% of the state population as per the 2011 Census. Hindus form a majority in 17 out of the 29 districts of Assam. By region, there is a significant diversity among the ethnic groups that profess the Hindu faith, traditions, and customs. As per as 2011 Census, In Brahmaputra Valley of Assam, Hindus constitute 62% of the population, the majority being ethnic Assamese. In the autonomous Bodoland region of Assam, Hindus constitute 71.3% of the region's population, most being of the Bodo tribe. In the Barak Valley region of southern Assam, Hindus constitute 50% of the region's population, most being ethnic Bengalis. The Hill Tribes of Assam, particularly the Karbi people of Karbi Anglong and Dimasa people of Dima Hasao, are mainly Animists.

Most of the Hindus in Assam belongs to the Ekasarna sect of Vaishnavism which is the dominant faith of the region since its formation from 15th–16th century in Brahmaputra valley, Assam. The Ahom kings during their 600 yrs rule in Assam, have increasingly patronizing Hinduism alongside the proselytizing activities of Ekasarana Dharma since the 16th-century—a large section of the Bodo-Kachari peoples converted to different forms of Hinduism in the 17th–18th century and a composite Assamese consisting of caste-Hindus, tribals began to form. Suhungmung, was the first Ahom king who have converted into Hinduism and adopt a Hindu title, Swarganarayana during that medieval period of ahom rule. But some sources also argue that Jayadhwaj Singha was the first Ahom king who have formally accepted Hinduism. Rudra Singha was the first who announced publicly of his inclination towards Hinduism and consequently later on he became a disciple of a Hindu Brahman priest. The historical roots of the Hindu religion in Assam dates back to at least 4th–7th centuries when Varman dynasty were ruling in the region. Vedic sacrifices such as the Ashvamedha and other Brahmanical rites and rituals were prevalent in this region during that period. The form of Hinduism that developed in the Assam region has long been a complex negotiation link between Vedic traditions with indigenous folk practices and beliefs. Before the arrival of Hindu religion in the fertile valley of Brahmaputra, Majority of ethnic Assamese people practiced an indigenous religion known as Ahom religion, followed by Bodo people who professed Bathouism and various ethnic tribals like : Karbi, Dimasa, Mising and Rabha were practitioners of Animism prior to the coming of Hinduism in the valley.

The Vaishnavism which is a prominent sect of Hinduism in Assam do not believe in idol worship and perform "Naamkirtan", where the glory of formless Lord Vishnu is recited and chanted. There are two important cultural and religious institutions that influence the religious fabric of Assam: the "Satras", is a site of religious and cultural practice and the "Namghar", the house of prayers where religious people meet and pray together as a community.

The first day of Bohag bihu is called "Goru Bihu". Goru means cow. The first day is the bihu of cows and buffaloes. Goru bihu is related to the agricultural roots of Assam in rural areas. The day is dedicated to caring and upkeep of cattle (the wealth generator of farmers). Cows (sacred animal in Hinduism) are bathed and smeared with turmeric and pulses near pond, and are worshiped as part of the festivities by Assamese Hindu agriculturalists throughout Assam.

During Ambubachi Mela, hindu sages from all over India assemble in the temple to get blessings of Maa Kamakhya and uplift their knowledge Tantra Sadhana, which is known by the local name of "Tantra Mantra". Kamakhya is centre of Tantric worship.

Bathow Puja is an important religious festival of the Bodo-Kacharies of Assam, India. In this festival, indigenous bodo people worship a god known by different names like Gila Damra, Khuria Bwrai, Sri Brai (Shib bwrai), Bathow Bwrai etc. Among these festivals, Kherai is the most significant and important.

Hajo is a historic town set in the hills northwest of Guwahati, Assam, India. It is a sacred place for Hindus as a pilgrimage site. To the Hindus of Assam and world over, the Manikut Parbat of Hajo is the site of the 10th-century temple ruins and the 11th- to 16th-century temples complex for Vaishnavism as well as shrines of Shaivism and Shaktism.

Navagraha temple are an important pilgrimage sites devoted to Navagraha—the nine (nava) major celestial bodies (Grahas) meaning planets of Hindu astronomy. The temple is made up of stones. These celestial bodies are named Surya means (Sun), Chandra means (Moon), Mangala means (Mars), Budha means (Mercury), Brihaspati means (Jupiter), Shukra means (Venus), Shani means (Saturn), Rahu means (North Lunar Node) and Ketu means (South Lunar Node). Many temples in Southern parts of India contain a shrine dedicated to the Navagrahas (nine planets). However, the term Navagraha temples refers to a cluster of nine separate temples, each an abode of one of the Navagrahas.