Direct proof of use
The F-35 Lightning II is directly documented in the 2014 War Against the Islamic State through the U.S. Air Force F-35A strike at Wadi Ashai, Iraq, on April 30, 2019. U.S. Air Forces Central Command reported that two F-35A Lightning II aircraft conducted an air strike in support of Combined Joint Task Force - Operation Inherent Resolve.
The official account identified the mission as the F-35A's first combat employment. It said the aircraft used a Joint Direct Attack Munition against an entrenched Daesh tunnel network and weapons cache in the Hamrin Mountains, a target area described as able to threaten friendly forces.
Sources: AFCENT F-35A First Combat Employment
Timeline
The aircraft reached the theater shortly before the strike. U.S. Air Force reporting says F-35As from Hill Air Force Base, Utah, joined the Combined Forces Air Component team in the U.S. Central Command area of operations on April 15, 2019, during the type's first deployment to the CENTCOM area of responsibility.
On April 30, 2019, two F-35As struck the Wadi Ashai target. AFCENT's later April airpower summary repeated the same strike details and placed the mission inside Operation Inherent Resolve air operations in Iraq and Syria, where U.S. and coalition pilots flew strike and intelligence, surveillance, and reconnaissance sorties in support of coalition and partner ground forces.
Sources: AFCENT F-35A First Combat Employment, AFCENT April 2019 Airpower Summary
Operational role
In this conflict record, the F-35 appears as a U.S. coalition strike aircraft, not as a system transferred to Iraqi or Syrian partner forces. The public sources identify the operator as the U.S. Air Force, the variant as the F-35A, the mission as an air strike, and the target category as a Daesh tunnel network and weapons cache.
The documented role fits long-range strike and interdiction: the aircraft attacked a fixed ISIS tunnel-and-cache target in Iraq during the post-territorial phase of Operation Inherent Resolve. The public releases do not name the exact aircraft tail numbers, provide target coordinates, or publish a battle-damage assessment beyond the target description.
Sources: AFCENT F-35A First Combat Employment, AFCENT April 2019 Airpower Summary