Gopalswamyi Ayyangar represented the Province of Madras in the Constituent Assembly. He began his career in the Madras Civil Services in 1905 where he served as a Deputy Collector till 1919, from which he was promoted to the post of Collector and District Magistrate in 1920. From 1920 to 1937 he remained a public servant, serving in various posts with his final posting being as a member of the Board of Revenue in 1937.
His contribution to politics started with his appointment as the Prime Minister of Kashmir from 1937-1943. His tenure as the member of Council of State lasted from 1943-1947 during which he was the Chairman of the Committee for the Indianisation of Army and in 1948 headed the delegation that represented India at the United Nations in the persistent dispute over Kashmir.
The Indian Railways experienced remarkable growth and development in services and equipment under his leadership as the Minister for Railways and Transport from 1948–52.The regrouping of the Indian Railways into six zonal systems was his brainchild leading to the Railways reporting surplus earnings at this time. His report on "Reorganization of the Government Machinery" in 1949, which aimed at the smooth running of the government services, led to the formation of the Defence Committee, the Economic Committee, the Parliamentary and Legal Affairs Committee, and the Ad Hoc Administrative Organization Committee by the Central government.
In 1952, he was appointed as India's representative in the ongoing negotiations and discussions on Kashmir at the Geneva talks. His final stint was as the Defence Minister from 1952-1953.
- Member, Rules of Procedure Committee;
- Member, Order of Business Committee;
- Member, Functions Committee;
- Member, States Committee;
- Member, Union Powers Committee;
- Member, Union Constitution Committee;
- Member, Committee on Chief Commissioners Provinces;
- Member, Drafting Committee.