Abstract: A sealing device has a sensor system for condition monitoring. The sealing device includes a sealing ring with a dynamic sealing section for dynamically sealing abutment at a sealing surface of a machine part and a pretensioning ring for pretensioning the sealing section against the sealing surface having a first section and a second section. The second section can be deflected in a spring-elastic manner in an axial or radial direction relative to the central axis of the sealing device from a first position relative to the first section. The sensor system includes at least one measuring element arranged in the intermediate space on the pretensioning ring, which responds indirectly or directly to a deflection movement of the first section of the pretensioning ring. A sealing arrangement may have such a sealing device.