Arcandor AG (KarstadtQuelle AG until June 30, 2007) (FWB: ARO) is a holding company located in Essen, Germany, that oversees companies operating in the businesses of mail order and internet shopping, department stores and tourism services. It was created in 1999 through the merger of Karstadt Warenhaus AG, which was founded in 1920, and Quelle Schickedanz AG & Co, founded in 1927. In 2005, the corporation had about 68,000 employees and annual sales of €15.5 billion. Its stocks were traded on the Mid Cap DAX until September 2009. The company's largest store is Kaufhaus des Westens (KaDeWe) in Berlin, while the largest store under the name Karstadt is in Frankfurt. On May 11, 2009, the company requested government financial assistance due to liquidity problems. On June 6, 2009, the company announced that it is no longer able to pay rent for its department stores, which the company had previously sold and leasebacked. On June 9, 2009, the company filed for bankruptcy.

On 14 May 1881, Rudolph Karstadt founded his first store Tuch-, Manufaktur- und Konfektionsgeschäft Karstadt (Cloth, Manufacture, and Mass Production Business Karstadt) in Wismar. In 1884, a second store was opened in Lübeck. Soon, 24 stores had been opened in all of Northern Germany. In 1920, the business was turned into a joint stock company. In 1984, Karstadt acquired the mail-order business Neckermann Versand. In 1994, it acquired the department store chain Hertie, to which KaDeWe belonged. In 1999 it finally merged with Quelle AG to become KarstadtQuelle AG, only to be renamed Arcandor AG on July 1, 2007. The current chief executive officer is Karl-Gerhard Eick (since 2009).