69-year-old Dr Saha, who is a Rajya Sabha MP, was named as the leader of the BJP legislature party hours after the resignation of Deb.
Meanwhile, BJP leader Biplab Kumar Deb resigned from his post on Saturday. After submitting his resignation to State Governor Satyadeo Narain Arya, he said that he had wholeheartedly served the people of the state.
Deb had taken oath as the first Chief Minister of Bharatiya Janata Party in Tripura in 2018.
Tripura will go to the polls by March next year.