Combined Joint Task Force – Operation Inherent Resolve (CJTF–OIR) is multinational military formation established by the U.S.-led international coalition against the Islamic State of Iraq and the Levant (ISIL) with the stated aim to "degrade and destroy" the organization. Led by United States Army Central (ARCENT), it is composed of military forces and personnel from over 30 countries.

Formed in October 2014 by U.S. Central Command, CJTF-OIR was intended to replace the ad hoc arrangements that had been established to coordinate operations against ISIL, following its rapid gains in Iraq in June. Its central military operation, Inherent Resolve, consists of campaigns in Iraq, Syria, and Libya. The current commander of the coalition is U.S. Army Major General John W. Brennan.

The bulk of CJTF-OIR's combat operations have consisted of airstrikes against Islamic State; ground forces have also been deployed in various capacities, including special forces, artillery, training, and military advisors. The United States accounts for the vast majority of airstrikes (75–80%), with the remainder conducted by Australia, Canada, Denmark, France, Jordan, Belgium, the Netherlands, Saudi Arabia, Turkey, the United Arab Emirates, and the United Kingdom. Although the task force is not under NATP, all 29 members of the military alliance are also contributors to CJTF-OIR.

By the end of 2017, CJTF-OIR stated that its airstrikes had killed over 80,000 ISIL fighters. The coalition also provided $3.5 billion in military equipment to the Iraqi Armed Forces, billions more to the Peshmerga, and trained 189,000 Iraqi soldiers and police. It has also provided significant support to the Syrian Democratic Forces, with which it coordinates various operations.