Sects of Sikhism are sub-traditions within Sikhism that believe in an alternate lineage of Gurus, or have a different interpretation of the Sikh scriptures, or believe in following a living guru, or other concepts that differ from the orthodox. The major historic sects of Sikhism, states Harjot Oberoi, have included Udasi, Nirmala, Nanakpanthi, Khalsa, Sahajdhari, Namdhari Kuka, Nirankari and Sarvaria.
The early Sikh sects were Udasis and Minas founded by Sri Chand – the elder son of Guru Nanak, and Prithi Chand – the elder son of Guru Ram Das respectively, in parallel to the official succession of the Sikh Gurus. Later on Ram Rai – son of Guru Har Rai formed his own sect at Dehradun and his followers are called Ram Raiyass. Many splintered Sikh communities formed during the period between the death of Guru Har Krishan and the coronation of Guru Tegh Bahadur. These sects have had considerable differences. Various other Sikh sects emerged over the Sikh history. Some of these sects were financially and administratively supported by the Mughal Empire in the hopes of gaining a more favorable and compliant citizenry.
In the 19th century, Sanatan Sikhs, Namdharis and Nirankaris sects were formed in Sikhism, seeking to reform and return to what each believed was the pure form of Sikhism. They also accepted the concept of living Gurus such as Guru Baba Dyal Singh. The Nirankari sect though unorthodox was influential in shaping the views of Tat Khalsa and the contemporary era Sikh beliefs and practices. Another significant Sikh sect of the 19th century was the Radhasoami movement in Punjab led by Baba Shiv Dyal. Other contemporary era Sikhs sects include the 3HO Sikhism, also referred to as Sikh Dharma Brotherhood formed in 1971.