The Big Willis Mall is a shopping mall on Saratoga Ave in Willis, Dukes, Liberty City. The mall is not accessible to the player. Businesses in the mall include Al Dente's, Anna Rex, Canyon Megaplex, Didier Sachs, Pill Pharm, Pizza This, and Ranch. The mall is a destination for Taxi Driver in Grand Theft Auto: Chinatown Wars.
The name of the mall is a possible joke. It refers to the cultural word for a penis in Britain, "willy", thus creating amusement due to the word "Big" before "Willis" which refers to a "large penis".