Former Taliban Chief Mullah Mansour was killed in a US drone strike in Pakistan's Balochistan province
Haibatullah was one of two deputies under Mansour, who was killed in a US drone strike on Saturday, the first known American assault on a top Afghan Taliban leader on Pakistani soil.
"Haibatullah Akhundzada has been appointed as the new leader of the Islamic Emirate (Taliban) after a unanimous agreement in the shura (supreme council), and all the members of shura pledged allegiance to him," the Islamist group said in a statement.
It added that Sirajuddin Haqqani, an implacable foe of the US, and Mullah Yakoub, the son of Taliban founder Mullah Omar, were appointed his deputies.
Mansour's killing is a major blow to the militant movement just nine months after he was formally appointed leader following a bitter power struggle, and sent shockwaves through the leadership.
Haibatullah's appointment comes after the Taliban's supreme council held emergency meetings that began Sunday in southwest Pakistan to find a unifying figure for the leadership post.
Taliban sources told AFP the supreme council members were lying low and constantly changing the venue of their meetings to avoid airstrikes.