Conor Anthony McGregor is an Irish professional mixed martial artist. He is a former Ultimate Fighting Championship (UFC) Featherweight and Lightweight Champion, becoming the first UFC fighter to hold UFC championships in two weight classes simultaneously. He is also a former simultaneous Cage Warriors Fighting Championship (CWFC) Featherweight and Lightweight Champion.
In 2008, McGregor began competing professionally in mixed martial arts (MMA), fighting in the lightweight and featherweight divisions. He won the CWFC Featherweight and Lightweight Championships in 2012 before signing with the UFC in 2013. After five consecutive wins, he won the Interim Featherweight Championship by defeating Chad Mendes at UFC 189. He became the undisputed Featherweight Champion at UFC 194 after knocking out José Aldo in 13 seconds, which is the fastest finish in UFC title fight history. In 2017, he won the UFC Lightweight Championship at UFC 205 by defeating Eddie Alvarez. He transitioned briefly to professional boxing, facing Floyd Mayweather Jr. in a highly publicised bout, which he lost via TKO in the 10th round.