Actor Nathan Fillion, best known for his roles in the ABC series "Castle" as the eponymous character and in "Firefly" as the lead role, is not and has not been married, as of August, 2015. Rumors had been circulating that he was secretly married, but they were proven false.
Fillion's past romantic encounters include his four-year relationship with actress Perrey Reeves from 2005 to 2009. This was followed by his relationship with "Castle" co-star Stana Katic, who played the love interest of his character. Their relationship lasted from 2009 to 2012. As of August 2015, his most recent girlfriend is actress Krista Allen.