80-year-old Naik was administered oath of office by Chief Justice of Allahabad High Court Justice Dhananjaya Y Chandrachud this evening.
Chief Minister Akhilesh Yadav, several ministers, MLAs, senior bureaucrats and senior officers from police department were present on the occasion.
Veteran BJP leader Ram Naik succeeds BL Joshi, who resigned last month. Joshi, perceived to be a close confidant of Gandhi family, was the first Governor who tendered his resignation on June 17 after the Narendra Modi government came to power.
A three-time Parliamentarian, Naik has the rare distinction of being the only minister who completed five years as Petroleum and Natural gas minister in one government.
Hit by cancer, Naik was bedridden in 1994 but fought back resolutely and overcame the deadly disease. He had announced in 2013 that he would not be contesting the 2014 elections.