Fighter attack squadrons of the United States Marine Corps

Marine Fighter Attack Squadron 121 (VMFA-121), also known as the "Green Knights", is a United States Marine Corps aircraft squadron operating the F-35B Lightning II. The squadron is based at Marine Corps Air Station Iwakuni, Japan and falls under the command of Marine Aircraft Group 12 (MAG-12) and the 1st Marine Aircraft Wing (1st MAW). Their tail code is VK and their radio call sign is "Combat".