He is a 1984 batch retired IAS officer.
The Legislative Department of the Ministry of Law and Justice issued a notification on Friday regarding the appointment of Rajiv Kumar.
He took over as Finance Secretary in the month of July last year and held this position till March this year.
Rajiv Kumar will replace Election Commissioner Ashok Lavasa, who will be free of charge on August 31.
Ashok Lavasa had sent his resignation on tuesday from the post of Election Commissioner to Rashtrapati Bhavan and President had accepted his resignation on Wednesday.