840 Zenobia is a minor planet orbiting the Sun. It was discovered by German astronomer Max Wolf at Heidelberg on September 25, 1916. The origin of the name is uncertain, but it may be named after the Slavic god of the hunt. Photometric observations of the asteroid during 2006 at the Palmer Divide Observatory in Colorado Springs, Colorado, were used to generate a light curve with a period of 5.565 ± 0.005 hours and a variation in brightness of 0.20 ± 0.02 magnitude.