Michael J. Fox became a major movie star thanks to his starring role in the "Back to the Future" flicks ... and this weekend, he turns 51.
Fox, whose birthday was yesterday, has had a hugely successful career since playing the time traveling teen -- going on to continue work on "Family Ties," as well as starring in movies and shows like "Spin City," "Teen Wolf," "The Frighteners."
He also earned an Emmy for a guest starring role on "Rescue Me."
Fox was diagnosed with Parkinson's disease in 1990, but didn't go public with the news until 1998 -- and has since become one of the biggest advocates for research.
His wife Tracy Pollan has remained by his side through it all and the couple has four children together.
Check out how Fox and all of his :"Back to the Future" costars have aged since the first movie came out in 1985 in the gallery above!