This list of largest buildings in the world ranks buildings from around the world by usable space (volume) and floor space (area). The term 'building' used by this list refers to single structures that are suitable for continuous human occupancy. There are a few exceptions which include factories and warehouses.

Boeing's factory in Everett, Washington, United States is presently the largest building by volume while the Aalsmeer Flower Auction in The Netherlands was the largest building by area until the construction of Terminal 3 of Dubai International Airport. The floor area of the proposed Crystal Island complex in Moscow is more than double that of the largest current building, though this project has been delayed indefinitely by the global economic crisis.