Gosains (गोसाईं), who are also known as Gossain, Gosine, Gossai, Gosyne, Gosein, Gosavi, and as Goswamis, are Brahmins, Hindu ascetics and religious functionaries of India. Found chiefly in northern, central and western India, they have different histories by place and time. Even the name Goswami has been variously interpreted as 'master of cows', 'master of mind or intellect', 'master of senses or emotions' and 'master of passion'. The Goswamis have strong historical ties with the Rajputs (Kshatriyas) as they were highly respected and given high positions by the Rajput Kings. The Goswamis were also Gurus (teachers) and royal advisors of the Rajputs.

The members of Dashnami Sect, believed to be the first brahmanical order of ascetics founded by Adi Shankaracharya, use the surname Goswami, Gosain or Gosavi which means a man who has attained complete control over sense organs. Many of the married Gosains officiate as priests and religious teachers. By the end of eighteenth century, the Gosains of this particular sect became a politically powerful group in northern India and also held and enjoyed Jagirs, pensions and titles. They are sometimes referred to more generally as Sannyasis.

In the sect of Vallabhacharya, the Pushtimarg, Brahmin religious leaders and spiritual heads of the tradition use Goswami and sometimes Gosain as surname and are addressed with the same as an honorific.

The chief disciples of Chaitanya Mahaprabhu, the founder of Gaudiya sect, namely the Six Goswamis, along with other followers and their lineages use Goswami as title and surname.

In the Ekasarana Dharma, a sect propagated by Sankardev, the hereditary heads and religious functionaries of Satras of Assam use the surname and title of Gosain and Goswami.

The Vaishnav Brahmins of region from UP to Bengal associated with Ramanandi sect started using the title 'Gosain-ji', which gradually replaced the term 'Guru' (teacher) as an honorific, and the same became a surname of Bairagi caste as well. The instance is reported by Buchanan in his memoirs while travelling in district of modern day Bihar. By 1910, the term was fully accepted as a credible title for both Shaivas and Vaishnavas as is reported in village-to-village surveys where Vaishnav temples are described as been erected or inhabited by Gosains.

Gosains were also Shaivite priests in most of the areas where their population was significant. They were often associated with Thakurbari in Eastern India and Mutts and Temples in regions like Braj where they possessed strong religious connotation.

The ascetic Gosains were powerful nomadic and mercenary trading groups who undertook pilgrimages across significant areas of land and they were important to urban economies and the development of wider trade networks. These itinerant religious groups could be very large in number, with figures in excess of 50,000 being probable for those headed by figures such as Umrao Giri and Himmat Bahadur Anup Giri Gosain in the late 1700s. Their numerical strength enabled them to be self-protecting and also to protect the trade routes that they used, regardless of who might have titular power in any given place. One out of at least three separate events that are grouped as Sanyasi Rebellion involved Gosains along with other instances of their frequent clashes with Company's army in northern frontiers of Bengal. Their movements were often dictated by religious festivals, both of a localised village nature and of a more widely celebrated type, such as Holi. As these festivals were also occasions for seasonal markets, so the Gosains were able to move and trade goods between areas.