The 2001 Unforgiven was the fourth annual Unforgiven professional wrestling pay-per-view (PPV) event produced by the World Wrestling Federation (WWF, now WWE). It took place on September 23, 2001, at the Mellon Arena in Pittsburgh, Pennsylvania. It was the final Unforgiven event held under the WWF name as the promotion was renamed to World Wrestling Entertainment (WWE) in May 2002. It was also the last Unforgiven held before the introduction of the brand extension in March 2002.

The main event was a standard wrestling match for the WWF Championship. Alliance representative Stone Cold Steve Austin defended the title against WWF representative Kurt Angle. Angle defeated Austin to win the title by forcing him to submit to the Ankle Lock. Other prominent matches were The Rock versus Booker T and Shane McMahon in a Handicap match for the WCW Championship, and Rob Van Dam versus Chris Jericho for the WWF Hardcore Championship.

The undercard featured Tajiri versus Rhino for the WCW United States Championship, Brothers of Destruction (The Undertaker and Kane) versus KroniK (Brian Adams and Bryan Clark) for the WCW Tag Team Championship, Edge versus Christian for the WWF Intercontinental Championship, Perry Saturn versus Raven. The night kicked off with Dudley Boyz (Bubba Ray Dudley and D-Von Dudley) versus Big Show and Spike Dudley, Lance Storm and The Hurricane and Hardy Boyz (Matt Hardy and Jeff Hardy) in a Fatal Four-Way Elimination match for the WWF Tag Team Championship.