According to one embodiment, an X-ray computed tomography apparatus includes a gantry for imaging a subject by X-ray CT and a console communicably connected to the gantry. The gantry includes a gantry body and a column unit. The gantry body has a bore into which the subject is inserted when the subject is imaged by X-ray CT. The column unit includes a first column which supports the gantry body slidably in a direction perpendicular to a floor surface and a second column which supports the first column slidably in a vertical direction.