Sean Penn has been a Hollywood star for over thirty years, but there's still plenty to know about the Oscar-winning actor.

Born in Southern California, Penn got his start as a teenager under the tutelage of his once-blacklisted father. After several supporting turns in the early '80s, most memorably as Spicoli in "Fast Times in Ridgemont High" (1982), the future star's career could have easily stalled. Instead, Penn smoothly transitioned to dramatic roles and quietly solidified his place as a leading man. This week, he's back in action and starring in "The Gunman."

From his appearance on "Little House on the Prairie" to his complicated love life, here are 17 things you probably don't know about Sean Penn.

[Sources: IMDb, Wikipedia]

sean penn facts