World Series of Fighting, also known as WSOF, is an American mixed martial arts (MMA) promotion based in Las Vegas, Nevada. The inaugural WSOF event took place on November 3, 2012 and the main card was broadcast on the NBC Sports Network.

On May 15, 2013, WSOF announced a 4 man tournament to crown an Inaugural Middleweight Champion that will take place at WSOF 5. The participants announced are as followed: Jesse Taylor, Elvis Mutapcic, David Branch & Danillo Villefort

World Series of Fighting 13: Moraes vs. Bollinger was a mixed martial arts event held September 13, 2014 in Bethlehem, Pennsylvania, United States, The event aired on NBCSN.