Sharma was born in Sabzi Mandi, Delhi. He grew up with his 6 brothers and 1 sister. He did his schooling from Ramjas School, Karolbagh. He did his higher studies from the Shri Ram College of Commerce (SRCC) and joined Akhil Bhartiya Vidyarthi Parishad.
In 1997, he married Ritu Dhawan.
After having completed his Master’s degree (M Com), he was hired as a researcher by Janardan Thakur, a journalist who had just quit Ananda Bazar Patrika to start a new syndicate column. Subsequently, he joined the Onlooker Magazine as a trainee and then went on to become its editor in 1985. By this time, Rajat Sharma had shifted base to Mumbai. After having spent three years at Onlooker, he joined Sunday Observer as an editor and later on The Daily again as the editor. Employees at The Daily found out he doesn’t know how to write editorials in English and he hired Mr. V. Gangadar to write as him. Then he was forced to resign from the position of the editor after the strike of The Daily employees.
It was in 1992 that he bumped into Zee TV’s Subhash Chandra during a flight to Delhi and it was in the midst of a casual conversation that the concept of Aap Ki Adalat took shape. In 1993, the first episode of Aap Ki Adalat was shot for Zee TV with Lalu Yadav, the former-Chief Minister of Bihar. Rajat Sharma has interviewed more than 750 guests on his show and recently Aap Ki Adalat celebrated 21 years of broadcast thereby making it the longest running show in India’s television history. He also hosts the prime time show Aaj Ki Baat on India TV.
He was amongst one of the President of Delhi Cricket Association.