The Ultimate Fighter: United States vs. United Kingdom is the ninth installment of the Ultimate Fighting Championship (UFC) produced reality television series The Ultimate Fighter. It began production in January 2009, and began airing on Spike on April 1, 2009. The season featured Lightweight fighters (146–155 lb) and Welterweight fighters (156–170 lb). In order to be considered for the show, a fighter had to have competed in at least three professional bouts prior to the tryouts in October 2008.

Diego Sanchez is an American professional mixed martial artist who currently competes on the Super Lightweight division of Eagle Fighting Championship. A professional competitor since 2002, Sanchez is most known for his time in the Ultimate Fighting Championship (UFC), where he won the Middleweight tournament of The Ultimate Fighter 1. He has also formerly competed for King of the Cage, where he was the Welterweight Champion.