This letter proposes a double-resonator sensor for simultaneous temperature and magnetic-field detection. Whis-pering-gallery-mode resonators have shown promise due to their high-quality factors and high sensitivity. In this work, hollow and solid whispering gallery mode resonators were coupled to a tapered fiber, with the hollow reso-nator filled with magnetic fluid. The solid resonator was built with PMMA. The sensor exhibited a 121 pm/°C re-sponse to temperature changes within the 20--80 °C range. The double-resonator sensor reached a 9 pm/mT response to magnetic field variations in the 0-100 mT range. The proposed sensor demonstrated that whispering-gallery-mode resonator sensors are suitable for building compact magnetic-field and temperature sensors.