Abu Halil Al Fadani, described as an operational and facilitation official for the terrorist group, was detained by US Central Command Forces on September 23, US Central Command said.
“The capture of ISIS officials like Al Fadani increases our ability to locate, target and remove terrorists from the battlefield,” Centcom spokesman Lt Col Troy Garlock said.
About 900 US troops are in Syria as part of the US-led coalition to defeat ISIS, which maintains a presence across Iraq and Syria.
US forces regularly conduct helicopter raids and air strikes against suspected ISIS militants in northern Syria.
Mr Al Fadani "was assessed to have relationships throughout the ISIS network in the region", Centcom said.
Remnants of ISIS often stage attacks against the Kurdish-led Syrian Democratic Forces, a key US ally in the fight against the terrorist group.
American drones used in counter-terrorism operations have also been harassed by Russian aircraft, sparking criticism from Washington.
Senior US officials have warned ISIS could return to Syria "within one to two years" if American troops leave the country.
US troops also remain in Iraq, where coalition forces often stage air strikes against ISIS suspects in the northern Hamrin Mountains.
Their presence has been criticised, with Iraq Prime Minister Mohammed Shia Al Sudani having said that Baghdad no longer needs US troops in the country.
Iraq has now formed a joint committee with the US to explore "future relations" with the international coalition.
About 5,000 American troops remained in Iraq as part of the US-led coalition after the recapture of Mosul from ISIS in 2017.
US troops numbers were reduced by President Donald Trump and American forces switched their focus to advising and training Iraqi forces in the fight against ISIS sleeper cells.