US Africa Command said that Abdulhakim Dhuqub was killed Sunday in the strike vicinity of Xiriiro in the Bari region.
In the current assessment, the US military said the strike killed only Dhuqub and destroyed one vehicle.
"Dhuqub was responsible for the daily operations of the extremist group, attack planning and resource procurement," AFRICOM said in a statement.
The Islamic State group has a relatively small presence in Somalia, where Al-Shabaab fighters are more powerful and aligned with Al-Qaeda.
"We continue to work with our Somali partners to keep pressure on the Al-Shabaab and ISIS-Somalia terror networks," said AFRICOM director of operations Marine Corps Major General Gregg Olson.
"When it supports the strategy, we use precision air strikes to target those who plan and carry out the violent extremist activities that put Somalis at risk."
In late 2018, the US military estimated that there were between 75 and 250 Islamic State fighters in Somalia, compared to 3,000 to 7,000 Shabaab fighters.