A communications system includes cellular devices and cellular base stations in communication with the cellular devices in a first frequency band. A non-geostationary satellite may include sensing circuitry operable in a second frequency band susceptible to interference from the first frequency band. Each cellular base station may include a controller and a transceiver cooperating therewith. The controller may be configured to store satellite path data for the non-geostationary satellite, determine when the satellite path data indicates interference would otherwise be experienced by the non-geostationary satellite, and implement an interference mitigation action in cooperation with associated cellular devices based upon the satellite path data indicating interference would otherwise be experienced by the non-geostationary satellite.