Veteran referee Marc Goddard was unanimously selected to oversee the July 7 superfight Thursday at a meeting of the Nevada Athletic Commission.
In addition, commission officials selected a trio of Las Vegas regulars to judge the bout: Dave Hagen, Chris Lee, and Glenn Trowbridge.
The judges for that bout will be another threesome of Las Vegas regulars: Derek Cleary, Sal D’Amato, and Junichiro Kamijo.
Goddard and Dean will be paid $1,900 for their work, while the six judges will each earn stipends of $1,600, per commission officials.
UFC 226 takes place at the T-Mobile Arena in Las Vegas, Nevada.
Miocic is the most decorated heavyweight champion in UFC history, having defended his title a record-breaking three times since his reign began in mid-2016.
Cormier, who holds an undefeated 13-0 record at heavyweight, is attempting to become only the second fighter in UFC history to hold two belts concurrently.
The two champions served as coaches on The Ultimate Fighter 27.