In addition to this, she has become the Minister for the Community and Voluntary Sector and Associate Minister for Social Development and Employment.
She has become New Zealand's first-ever Kiwi Indian Minister, the New Zealand Herald newspaper quoted Indian Weekender as saying.
Radhakrishnan, who is from the 2017 intake of new MPs, is a minister outside of the Cabinet.
She lives in Auckland with her husband.
Announcing the names of the new ministers, Prime Minister Ardern said: "I am excited to be bringing in some new talent, with first-hand experience in the areas that they will be working in, and reflecting the New Zealand that elected us on the 17th of October”.