UFC Fight Night: Santos vs. Walker was a mixed martial arts event produced by the Ultimate Fighting Championship that took place on October 2, 2021 at the UFC Apex facility in Enterprise, Nevada, part of the Las Vegas Metropolitan Area, United States.

Walker Johnny da Silva Barra de Souza, best known as Johnny Walker, is a Brazilian professional mixed martial artist. He currently competes in the Light Heavyweight division in the Ultimate Fighting Championship (UFC). A professional competitor since 2013, Walker gained entrance into the UFC by competing on Dana White's Contender Series and also previously competed for Jungle Fight in his native Brazil. As of December 19, 2023, he is #7 in the UFC light heavyweight rankings.