derived from Sanskrit nirmala meaning spotless, unsullied, pure, bright, etc., is the name of a sect of Sikhs primarily engaged in religious study and preaching. The members of the sect are called Nirmala Sikhs or simply Nirmalas. The sect arose during the time of Guru Gobind Singh (1666-1708), though some, on the authority of a line in the first varof Bhai Gurdas (D. 1636), claim, like the Udasis, Guru Nanak (1469-1539) himself to be the founder. Guru Gobind Singh wanted his followers not only to train in soldierly arts but also to cultivate letters. Especially during his stay at Paonta, on the bank of the River Yamuna, from 1685 to 1688, he had engaged a number of scholars to translate Sanskrit classics into current Braj or Punjabi, in order to bring them within easy reach of the less educated people. Guru Gobind Singh once asked one of these scholars, Pandit Raghunath, to teach Sikhs Sanskrit. The latter politely excused himself on the plea that Sanskrit was deva bhasa, language of the gods, and could not be taught to Sudras, i.e. members of the low castes. To even this caste bias Guru Gobind Singh sent five of his Sikhs, namely Karam Singh, Vir Singh, Ganda Singh, Saina Singh and Ram Singh, dressed as upper-class students, to Varanasi, the centre of Hindu learning. These Sikhs worked diligently for several years and returned to Anandpur as accomplished scholars of classical Indian theology and philosophy. In view of their piety and their sophisticated manner, they and their students came to be known as Nirmalas, and were later recognized as a separate sect.

After the evacuation of Anandpur in 1705, the Nirmala preachers went to different places outside the Punjab, particularly to Haridvar, Allahabad and Varanasi where they established centres of learning that exist to this day-Kankhal, near Haridvar, Pakki Sangat at Allahabad, and Chelan Math and Chhoti Sangat atVaranasi. When, during the second half of the eighteenth century, the Sikhs established their sway over the Punjab, some of the Nirmala saints came back here and founded at different places centres which were liberally endowed by Sikh chiefs.

It was customary for Nirmala scholars to attend, along with their disciples, religious fairs at prominent pilgrimage centres such as Haridvar, Allahabad and Gaya, where they, like other sddhus, took out shahis or processions and held philosophical debates with scholars of other religious denominations as a part of their preaching activity. Sometimes these scholastic exercises led to bitter rivalry and even physical confrontation. During the Haridvar Kumbh in 1855, a general meeting of the Nirmalas held in their principal dera at Kankhal took the first concrete step towards setting up a central body by electing Mahitab Singh of Rishikesh, reputed scholar of the sect, as their Sri Mahant or principal priest. Mahitab Singh attracted attention of the rulers of Patiala, Nabha and Jind with whose help a panchaiti akhara named Dharam Dhuja was established at Patiala in 1861. Its formal inauguration took place on 7 August 1862. The headquarters of the sect, however, remained at Kankhal. The sect comprises several sampradayas or sub-sects each with its own dera and its own following.

The Nirmalas believe in the Ten Gurus and Guru Granth Sahib. Taking the baptism of the Khalsa is not compulsory nor common among them. As a distinguishing mark of the sect they don at least one of the garment in ochre colour. They generally practise celibacy and are devoted to scriptural and philosophical study, but by tradition they are inclined towards classical Hindu philosophy especially Vedanta. Their contribution towards the preaching of Sikh doctrine and production of philosophical literature in Sanskrit, Braj, Hindi and Punjabi is considerable. Some of the important works that contributed to Sikh learning in general and the elucidation and regeneration of Sikh principles in particular are as follows: Sangam Sar Chandrika by Pandit Sadda Singh of Chetan Math, Varanasi, is commentary on a Sanskrit work on Advait philosophy, Advait Siddhi, Pandit Tara Singh Narotam (182291) wrote several books of which Gurmat Nirnaya Sagar (1877) and Guru Girdrath Kosh in two volumes (1889) deal with philosophy of Sikh religion. His Sri Guru Tirath Sangrahi is a pioneer work on historical Sikh shrines in and outside India. Another famous Nirmala scholar Pandit Sadhu Singh wrote Shri Mukh Uakya SidhantJyof and Guru Sikhya Prabhakar (1893). Giani Gian Singh (1822-1921) is known for his contribution to Sikh history. His Panth Prakash in verse appeared in 1880 and Twarikh Guru Khalsa in prose in 1891.