McGregor, who was rumored at one point to be in talks for this year's WrestleMania, was asked by street reporters in New York on Wednesday about Ronda Rousey signing with WWE.
"I'm delighted for her, absolutely over the moon for her! She looked like she really enjoyed herself at the event and I was very, very happy to see her."
McGregor, who called the current generation of WWE superstars and talent "dweebs", said that he's happy to see Rousey have fun with the company that been a fan of.
"She's a pioneer for the game. She's came through it all and faced big wins and big, big losses and she came through it and it's great to see her represent herself and mixed martial arts and have fun in the WWE. I know she's been a big fan of it all through her life, so it's great to see that."