Pushkar Singh Dhami on Wednesday took oath as the Uttrakhand chief minister during a ceremony held at Parade Ground in the presence of Prime Minister Narendra Modi.
This is 46-year-old Dhami's second consecutive stint as the chief minister.
Dhami and his eight ministers were administered the oath by Uttarakhand Governor Lt Gen (retd) Gurmit Singh.
Speculation over the CM's post in Uttarakhand had ended on Monday, when the BJP declared that the former Khatima MLA will lead the state government.
Dhami, under whose leadership the party had contested the just-concluded Assembly polls, had lost the elections from Khatima, the constituency he had been representing since 2012.
Dhami needs to be elected to the state Assembly within six months to continue as chief minister.
The BJP had won 47 of the 70 Assembly seats in the elections, the results of which were declared on March 10.