UFC 75: Champion vs. Champion was a mixed martial arts event held by the Ultimate Fighting Championship. The event was held September 8, 2007, at The O2 in London, United Kingdom.

Mirko Filipović, better known by his ring name Mirko Cro Cop, is a Croatian former professional mixed martial artist, kickboxer and amateur boxer. He is mostly known for his time in Pride Fighting Championships. Cro Cop fought in the UFC, K-1, RIZIN and Bellator. He is widely considered one of the greatest Heavyweight Kickboxers and MMA fighters of all time.