Elysium Mons is a volcano on Mars located in the volcanic province Elysium, at , in the Martian eastern hemisphere. It stands about above its base, and about above the Martian datum, making it the third tallest Martian mountain in terms of relief and the fourth highest in elevation. Its diameter is about , with a summit caldera about across. It is flanked by the smaller volcanoes Hecates Tholus to the northeast, and Albor Tholus to the southeast.