皇室堡（英文：Windsor House，以前叫做The IN Square），係香港銅鑼灣區內主要商場之一，喺香港島銅鑼灣告士打道311號。
Windsor House (formerly known as The in Square) is one of the major shopping malls in Hong Kong's Causeway Bay district, located at 311 Gloucester Road, Causeway Bay, Hong Kong Island.