Santali is a language in the Munda subfamily of Austro-Asiatic, related to Ho and Mundari. It is spoken by about six million people in India, Bangladesh, Nepal, and Bhutan. Most of its speakers live in India, in the states of Jharkhand, Assam, Bihar, Orissa, Tripura, and West Bengal. Santali is spoken by the Santhals.

The Santali alphabet, which is also known as Ol Cemet', Ol Ciki or simply Ol, was created in the 1920s by Pandit Raghunath Murmu as part of his efforts to promote Santali culture. Every other major language in India had its own alphabet, so he thought Santali should as well. Until the invention of this alphabet, Santali was either not written at all, or was written with the Bengali or Oriya alphabets. Christian missionaries prefer to write Santali with the Latin alphabet.