A high-voltage bushing includes an insulating body disposed concentrically around a cylindrical winding support formed of electrically conductive material, and a sealing device for sealing a gap between the winding support and the insulating body. The sealing device includes a sealing element disposed in a circumferential sealing groove. The circumferential sealing groove is disposed in the winding support and accommodates the sealing element. A method for producing a high-voltage bushing includes placing an insulating body concentrically around a cylindrical winding support formed of electrically conductive material. The insulating body has mutually concentrically disposed insulating layers. A sealing element is introduced into a circumferential sealing groove in the winding support, and the insulating body is subsequently impregnated with a resin to seal a gap between the winding support and the insulating body.