An object of the present invention is to provide a radio-frequency coil device that can be brought into close contact with a subject regardless of a size of the subject and can obtain a high-quality MRI image. The radio-frequency coil device includes at least one flexible coil unit, and a fixture is disposed to surround an outer periphery of the coil unit. The fixture includes, for example, a pair of panels disposed on both sides of the coil unit, and a fixing belt that is provided between the panels and fastens and fixes the panels. The coil unit is deformed by fastening the fixture, to be disposed in close contact with various head shapes.