Electrically insulating x-ray shielding devices in an x-ray tube. In one example embodiment, an x-ray tube includes an evacuated enclosure, a cathode and an anode at least partially positioned within the evacuated enclosure, and an electrically insulating x-ray shielding device proximate to the evacuated enclosure. The electrically insulating x-ray shielding device includes an oxide or nitride material having an atomic number from 57 to 74.