Which volcano is the largest known active shield volcano in the solar system?

Olympus Mons, located on Mars, is the largest volcano known in the solar system and the biggest shield volcano by far. It stands roughly 22 kilometers high, about two and a half times the height of Mount Everest above sea level. Its base spans hundreds of kilometers, making it a colossal volcanic structure. Although it is not known to be erupting today, it is classified as a volcanic shield built by repeated lava flows over a very long time.