The Century Building is a high rise office building in Chicago's Loop. It was designed by Holabird & Roche, and was built in 1915. It is a contributing property to the Loop Retail Historic District. The building is representative of the transition of Chicago high rise design from the Chicago School to Art Deco, and its north and east facades feature Neo-Manueline ornamentation. It is owned by the General Services Administration and currently sits vacant.

Originally known as the Buck & Rayner Building or the Twentieth Century Building, the building was completed in 1915. Buck & Rayner was a Chicago chain of drug stores, and commissioned the construction of the building. It occupied the corner store and basement. In 1917, Lake and State Savings Bank signed a twenty-year lease for the building's second floor. The bank's name was changed to the Century Trust and Savings Bank, and the building's name was changed to the Century Building.