Conor McGregor brought Cinco de Mayo to Ireland on Saturday -- throwing a massive Mexican-themed party to celebrate his son's 1st birthday!
The UFC star took over the fancy Kildare Hotel just outside of Dublin -- one of the nicest hotels in the country.
The party for Conor McGregor Jr. had everything from a live band to a balloon animal guy ... and, of course, the best food money can buy -- including lobster.
Conor's entire family showed up -- his mom, sisters and girlfriend Dee Devlin. Everyone appeared to have a great time .