The 125th Fighter Wing is an Air National Guard unit headquartered at Jacksonville International Airport, Florida, which operates the F-35A Lightning II airframe. The unit operates under the Air Combat Command (ACC) and is primarily tasked with aerospace control and air defense, ensuring rapid response capabilities for state and federal missions. In addition to its air defense responsibilities, the wing is postured to deploy globally in support of combat operations, humanitarian missions, and disaster relief efforts.

The 125th FW is organized into five groups: Operations, Maintenance, Mission Support, Medical, and Regional Support. Additionally, the wing commander has the support of several offices assigned to special staff and the air staff (A-staff).

The 125th FW staff is made up from a variety of functions. These functions include command and control, legal, plans and programs, safety, chaplains corps, public affairs, equal opportunity office, information protection, etc.

The 125th Operations Group is responsible for overseeing the 159th Fighter Squadron, which flies the F-35A Lightning II, and handles other functions such as airfield management, intelligence, and training and scheduling. It is also responsible for overseeing the 114th Electromagnetic Warfare Squadron.

The 125th Maintenance Group executes the responsibility of aircraft maintenance through the 125th Maintenance Squadron, 125th Aircraft Maintenance Squadron, and 125th Maintenance Operations Flight.

The 125th Mission Support Group leads several units including the 125th Civil Engineer Squadron, 125th Communications Squadron, 125th Security Forces Squadron, 125th Force Support Squadron, and the 125th Logistics Readiness Squadron. They are responsible for mission readiness and the day-to-day activities which keep the base operational.

The 125th Medical Group provides managerial, administrative and operational oversight for medical group personnel. The 125th Medical Group can provide basic lab work, immunizations, audiograms, dental evaluations, physical exams, bioenvironmental shop visits and public health services to all Airmen. The staff of mostly traditional guard members employs physicians, physician’s assistants, optometrists, dentists, nurses and med-tecs along with other specialty care providers.

The 125th Regional Support Group leads several specialized units including the 202nd Rapid Engineer Deployable Heavy Operational Repair Squadron Engineer (REDHORSE) Squadron, 290th Joint Communications Support Squadron, 159th Weather Flight and 131st Training Flight.

The Air National Guard's federal mission is to maintain well-trained, well-equipped units available for prompt mobilization during war and provide assistance during national emergencies (such as natural disasters or civil disturbances). During peacetime, the combat-ready units and support units are assigned to most Air Force major commands to carry out missions compatible with training, mobilization readiness, humanitarian and contingency operations.

When Air National Guard units are not mobilized or under federal control, they report to the governor of their respective state, territory (Puerto Rico, Guam, Virgin Islands) or the commanding general of the District of Columbia National Guard. Each of the 54 National Guard organizations is supervised by the adjutant general of the state or territory. Under state law, the Air National Guard provides protection of life, property and preserves peace, order and public safety. These missions are accomplished through emergency relief support during natural disasters such as floods, earthquakes and forest fires; search and rescue operations; support to civil defense authorities; maintenance of vital public services and counterdrug operations.