Weiss will take the lead on the studio's marketing efforts with executive vice president of creative affairs and acquisitions Stephanie Caleb.
She started her career at Saatchi & Saatchi Advertising and became corporate media director before moving on to senior positions at Dailey & Associates, among others.
'Emily has a proven track record of building entertainment brands and her depth and breadth of experiences makes her the perfect candidate to join our marketing team,' CEO Courtney Solomon said.
After Dark Films was founded in 2006 by Solomon and real estate and textile mogul Allan Zeman and aims to finance, produce and release one or two films a year in the $5-$20m range.
The company has a three-year output deal with Lionsgate and is perhaps best known for its After Dark Horrorfest - 8 Films To Die For.