- October 14, 1992: Born in Znojmo, Czechoslovakia (now the Czech Republic).

- 2011: Wins the Czech National Championships in Men’s Muay Thai (-86 kg).
- April 2012: Makes professional MMA debut for Gladiator Fighting Championship.

- December 7, 2013: Wins the inaugural GCF Light Heavyweight Championship against Martin Šolc.

- June 6, 2014: Defends GCF Light Heavyweight Championship against Tomáš Penz.










- December 29, 2015: Makes promotional debut for Rizin Fighting Federation, wins against Satoshi Ishii in the World Grand Prix 2015 –100 kg tournament.
- December 31, 2015: Advances to the finals of the World Grand Prix 2015 –100 kg tournament but loses to Muhammed Lawal.

- April 17, 2016: Defeats Kazuyuki Fujita at Rizin 1.

- September 25, 2016: Wins against Mark Tanios at Rizin 2 but suffers a knee injury.



- September 29, 2017: Returns to Light Heavyweight, wins against Willian Roberto Alves at Fusion FN 16.
- December 29, 2017: Wins against Karl Albrektsson at Rizin Fighting World Grand Prix 2017.


- July 28, 2018: Wins against Bruno Cappelozza at Rizin 11.
- September 30, 2018: Wins against Jake Heun at Rizin 13.



- December 31, 2018: Wins against Brandon Halsey at Rizin 14.


- April 21, 2019: Wins the inaugural Rizin FF Light Heavyweight Championship against Muhammed Lawal at Rizin 15.


- October 12, 2019: Wins against Fábio Maldonado at Rizin 19.
- December 31, 2019: Defends the Rizin Light Heavyweight Championship against C. B. Dollaway at Rizin 20 and signs with UFC.
- July 11, 2020: Makes UFC debut, wins against Volkan Oezdemir at UFC 251.





- May 1, 2021: Wins against Dominick Reyes at UFC on ESPN: Reyes vs. Procházka.



Cormier commented on strange USADA stats in 2022 saying:
“One of the reasons with Jon Jones was that he was gonna get to come back, but he was gonna be the most tested guy in USADA. They were gonna be on him. They were gonna make sure that he didn’t have picograms or any of that stuff. Where are his damn tests? I mean, why is he not the most tested?”
“Why are you testing Jiri Prochazka more than you’re testing this guy who has a history of having these types of issues? That makes no sense.”

“That’s not fair. That’s not random.”
“They say it’s random all the time, but not 64 times. Look, come on, seriously, he should be tested. Based on history, we’re through the year. Poor Jiri Prochazka is showing his wiener every six days, he’s having to get in front of that USADA guy. And, we have a guy, who has a history… that got tested a third of the months in a year.”
- June 11, 2022: Wins UFC Light Heavyweight Championship against Glover Teixeira at UFC 275.


- November 23, 2022: Vacates UFC Light Heavyweight Championship due to a shoulder injury.


- November 11, 2023: Loses to Alex Pereira for the vacant UFC Light Heavyweight Championship at UFC 295.

- April 13, 2024: Wins against Aleksandar Rakić at UFC 300.

- June 29, 2024: Loses rematch to Alex Pereira for the UFC Light Heavyweight Championship at UFC 303.