UFC 125: Resolution was a mixed martial arts event held by the Ultimate Fighting Championship on January 1, 2011 at the MGM Grand Garden Arena in Las Vegas, Nevada, United States.[3]
On October 26, 2010, Shane Carwin had to pull out of his fight with Roy Nelson due to a back injury that required surgery. Nelson was then pulled from the card altogether.[4]
On October 28, 2010, UFC president Dana White announced that World Extreme Cagefighting (WEC) would merge with the UFC and that WEC Featherweight Champion Jose Aldo would be promoted to UFC Featherweight Champion.[5] Josh Grispi was pulled from a planned WEC 52 bout with Erik Koch to challenge Aldo for the Featherweight title at this event.[6] However, Aldo was later forced off the card with an injury.[7] Grispi remained on the card and fought Dustin Poirier.[8]
A lightweight bout between Cole Miller and Matt Wiman, which was originally scheduled to take place at this event, was moved to UFC: Fight For The Troops 2.[9]
UFC 125 preliminary fights were shown live for the first time on Ion Television in the United States.[10] The preliminary fights were shown live in the United Kingdom on ESPN, Rogers Sportsnet in Canada[11] and Fuel TV in Australia.[12]