India was still a British colony when the International Astronomical Union was born in 1919. India did not have a national science academy nor a national research council at the time. The Royal Society, London, which was the adhering body of Great Britain to IAU, handled matters of the colony too. India formally joined the IAU in 1948 as an independent nation through an initiative taken by the Government of India. In 1968, the National Institute of Sciences of India (NISI) became the adhering organisation to the IAU, as did the other affiliate Unions of ICSU. Soon after, its name was changed to Indian National Science Academy (INSA).
Till the nineteen-sixties, individual Indian membership in the IAU grew rather tardily but the situation changed with the rapid growth of astronomical activities in the country. In 1967, M.K. Vainu Bappu, the then Director of the Kodaikanal Observatory, was elected a Vice-President of the Union. In 1979, he was elected the President of IAU for the triennium 1979–1982, and during the same period, V. Radhakrishnan and Govind Swarup were elected Presidents respectively of the Commisions 34 and 40. In 1985, the General Assembly of the Union was held in New Delhi. It was dedicated to the memory of Vainu Bappu who had initiated the process of inviting the Union to hold its GA in India. A few years later the Sixth Asian-Pacific Regional IAU Meeting was held in Pune. A number of IAU symposia and colloquia have also been held in the country. During the last three decades, the engagement of the Indian astronomers with IAU has increased a great deal with a large number of them taking on important official roles in the IAU. Currently, India has close to 300 individual members.