Singh and Sonia Gandhi were seated in the first row along with foreign heads of governments and states.
Former UPA ministers P Chidambaram, Sharad Pawar, Praful Patel, Jairam Ramesh and M M Pallam Raju were also present at the ceremony held at the forecourt of the majestic Rashtrapati Bhavan.
Former Prime Minister H D Deve Gowda and Samajwadi Party supremo Mulayam Singh Yadav were also present at the swearing-in ceremony.