Io is a moon of Jupiter, where things are seriously nuts. Not only does it have gigantic mountains way taller than any on Earth, it's also one of the most volcanically explosive places in the solar system. (Hmm, maybe she's so explosive because she's ticked off about orbiting a planet named after the god who caused her so many problems.) (Source.)
On the sci-fi TV series, Babylon 5, there's a space station called Io that orbits the Io, the moon. The station was also the sight of a battle called—you guessed it—the Battle of Io. You now know more about Babylon 5 than anyone your age. (Source.)
In the glitzy 2010 Clash of the Titans remake, a character named Io pops up to guide Perseus and tell him all about his birth. This Io doesn't have a whole lot to do with Io from Greek mythology, but she's still cool with us.
In DC's Wonder Woman comics, Io is the name of a butt-kicking Amazon blacksmith. Again, she doesn't have a whole lot in common with the original Io, but whatevs.