The bomber rammed a car filled with explosives into the vehicle carrying Nisar Ahmad Ahmadi, acting governor of northern Badakhshan, in the provincial capital Faizabad, Al Jazeera reported.
The driver was also killed and six others were wounded in the attack.
It was not clear who was behind the bombing, which was the first known attack on a Taliban official in Afghanistan in several weeks.
Muazuddin Ahmadi, the head of culture and information in the province, said the governor was the target of the attack.
Security has improved since the Taliban stormed back to power in August 2021, removing the US-backed government and ending their two-decade fighting, but Daesh (ISIL or ISIS) remains a threat.
The head of the province’s police force was killed in a suicide blast claimed by Daesh in December last year.
A bomb attack also killed the head of the mining department in April last year.
Daesh, which has a more sectarian agenda, poses the biggest threat to the Taliban’s authority in the country. It has killed and wounded hundreds of people, including foreigners and members of the minority Hazara, in a bid to undermine the Taliban government.
The terrorist group has also targeted Taliban administration officials, including claiming the killing of the governor of northern Balkh province in an attack on his office in March.
The Taliban administration has been carrying out raids against members of Daesh.