Champat Rai Jain (6 August 1867–2 June 1942) was a Digambara Jain born in Delhi and who studied and practised law in England. He became an influential Jainism scholar and comparative religion writer between 1910s and 1930s who translated and interpreted Digambara texts. In early 1920s, he became religiously active in India and published essays and articles defending Jainism against misrepresentations by colonial era Christian missionaries, contrasting Jainism and Christianity. He founded Akhil Bharatvarsiya Digambara Jain Parisad in 1923 with the aim of activist reforms and uniting the south Indian and north Indian Digambara community. He visited various European countries to give lectures on Jainism. He was conferred with the title Vidya-Varidhi (lit. Ocean of Wisdom) by Bharata Dharma Mahamandal (The India-Religious Association).

Champat Rai Jain was born on 6 August 1867 in Delhi, India. He was married at the age of 13. In 1892, he went to England to study law, and became a barrister.

Champat Rai Jain was a Digambara, whose writings represent that sect's propaganda with his personal interpretations, according to Robert Williams. Jain became a part of a Digambara group presenting Digambara point of view in the 1920s and 1930s such as with Jagadarlal Jaini, Nathuram Premi, Jugalkishor Mukhtar and Hiralal Jain. Jain was the founder of the Jaina mission in London. He died on 2 June 1942. He was a barrister-at-law, orator, writer, and attempted to explain Jainism with modern age psychology and science terminology.

According to Padmanabh Jaini, the colonial-era Champat Rai Jain was an apologist of Jainism, defended the Jain doctrines that were criticized by Christian missionaries, and authored the first Jaina text aimed at the Christian world when Christian missionaries were extremely frustrated at Jain people they understood to have "no pagan gods" and refused to convert to Christianity. He was among the early 20th-century Jain activists who participated in the colonial discussion about whether Jains are culturally Hindus or a minority community.

He became a part of Digambara activists who sought to energise and reform Digambara community. He participated in several Digambara societies, and founded Akhil Bharatvarsiya Digambara Jain Parisad in 1923 with the aim of activist reforms, reducing caste divisions within Jain society, and uniting the south Indian and north Indian Digambara community.

Champat Rai Jain attempted to present Jainism as a scientific religion:

Jainism is a science, and not a code of arbitrary rules and capricious commandments. It does not claim to derive its authority from any non-human source, but is, science-like, founded on the knowledge of those Great Ones who have attained perfection with its aid. Scientific validity can be claimed neither by dogmatism nor mysticism; and it is unnecessary to add that nothing but science and scientific thought can be relied upon to produce immediate, certain and unvarying results.

— Champat Rai Jain, Essays and Addresses