Vengeance (2001) was the first WWE Vengeance pay-per-view event produced by the World Wrestling Federation (WWF). It was presented by Lugz and took place on December 9, 2001, at the San Diego Sports Arena in San Diego, California, and it was the only event under the Vengeance banner to take place in December, replacing WWE's former December pay-per-view, WWE Armageddon.
The main feature of the event was a three-match tournament to unify the [[WWE Championship and the World Championship into what became known as the Undisputed WWF Championship.
- WWF Sunday Night Heat - The APA (Bradshaw and Faarooq) defeated Billy and Chuck
- Scotty 2 Hotty and Albert defeated Christian and Test
- Edge (c) defeated William Regal for the WWE Intercontinental Championship
- Jeff Hardy defeated Matt Hardy with Lita as the special guest referee
- The Dudley Boyz (Bubba Ray Dudley and D-Von Dudley) (c) (with Stacy Keibler) defeated Big Show and Kane for the WWE Tag Team Championship
- The Undertaker defeated Rob Van Dam (c) - Hardcore match for the WWE Hardcore Championship
- Trish Stratus (c) defeated Jacqueline for the WWE Womens Championship
- Stone Cold Steve Austin (c) defeated Kurt Angle for the WWE Championship
- Chris Jericho defeated The Rock (c) for the World Championship
- Chris Jericho (c) defeated Stone Cold Steve Austin (c) - Championship unification match for the World Championship and the WWF Championship unified into the Undisputed WWF Championship.