Mila Kunis -- Obsessed Fan Charged with Stalking

The man who was detained outside of Mila Kunis' L.A. gym earlier this month has just been charged with two counts of felony stalking.

According to the L.A. County District Attorney, 27-year-old Stuart Lynn Dunn was charged with two counts of felony stalking after cops say he followed Mila to her gym and waited in the parking lot ... three days in a row.

What's worse -- cops say Dunn had previously been ordered to stay away from Kunis for 3 years after he broke into a vacant condo she owned back in January and temporarily inhabited the property.