Liquid metal containment in an x-ray tube. In one example embodiment, an x-ray tube anode assembly includes a stationary shaft terminated by a head and an anode connected to an anode hub. The anode hub is at least partially surrounding the head of the stationary shaft. The anode hub defines a hub opening through which the stationary shaft extends. The anode hub is configured to contain a volume of a liquid metal and to rotate around the stationary shaft. The anode hub also defines a catch space within the anode hub that is configured to catch the liquid metal in order to contain the liquid metal within the hub regardless of the orientation of the x-ray tube anode assembly.