She wed artist Davey Detail, 37, on Saturday in Los Angeles, her rep confirms to PEOPLE exclusively.
The pair, who got engaged in July, exchanged vows in a "romantic and ethereal" ceremony as 60 guests looked on, a source tells PEOPLE.
McGowan, 40, wore a gown by Monique Lhuillier as the couple were married by a rabbi outdoors under a chuppah she designed herself.
"Hell to the yeah! I'm a Mrs.! What?! AWESOME!" she Tweeted early Sunday morning. "Love to you all!!!!!"