The Gauhati High Court was promulgated by governor general of India on 1 March 1948 after the Government of India Act 1935 was passed, establishing the high court with effect from 5 April 1948, for the then-province of Assam.

In exercise of power conferred by the Government of India Act 1935, the Governor General of India on 1 March 1948 promulgated the Assam High Court Order, 1948, establishing the High Court of Assam.

The Assam High Court initially had its sittings at Shillong but shifted to Guwahati on 14 August 1948.

This High Court was given jurisdiction over the then union territories of Arunachal Pradesh and Mizoram by section 32 of the Act.

The permanent bench at Itanagar was inaugurated on 12 August 2000 by A.S. Anand at Naharlagun, which is located about 13 km.

On 5 July 1990, the Aizawl permanent bench of the Gauhati High Court was established and inaugurated by the then-chief justice of India, S.B.