Nirmal Chandra Sinha (1911-1997) was an Indian tibetologist, author, the founder director of Sikkim Research Institute of Tibetology (SIRT), presently known as the Namgyal Institute of Tibetology, Deorali near Gangtok. He was known for his contributions to Buddhism and the documentation of the history of Tibet and other states of the Central Asia. He was honoured by the Government of India in 1971 with Padma Shri, the fourth highest Indian civilian award.