Party City Holdco Inc. is an American publicly traded retail chain of party stores founded in 1986 by Steve Mandell in East Hanover, New Jersey. Party City’s parent organization is Party City Holdings Inc. Based in Elmsford, New York, the company is the largest retailer of party goods in the United States, Canada and Mexico, operating over 900 company-owned and franchise outlets under the Party City, Halloween City, Toy City, and Factory Card & Party Outlet brands.