The 59-year-old Ranjan Mathai succeeds Nirupama Rao- whose last day in office was Sunday- and begin his two-year term from Aug 1.
Nirupama Rao retired on Sunday and her post-retirement high profile assignment is to take over as the Indian ambassador to the United States.
A 1974 batch Indian Foreign Service officer, Mathai has held a string of high-profile diplomatic positions. He was India`s ambassador to Israel February 1998 to June 2001, and to Qatar August 2001 to July 2005.
A veteran diplomat, he was joint secretary dealing with India`s relations with Bangladesh, Sri Lanka, Myanmar and the Maldives from January 1995 to February 1998.