McGregor faces off against 41-year-old Mayweather in the early hours of Sunday morning in Las Vegas.
Mayweather is the clear favourite to win the bout over the UFC star at the T-Mobile Arena.
But Ibrahimovic, who has resigned with Manchester United, believes the Irishman is ‘the Ibrahimovic of the martial arts world’ and is capable of causing an upset.
He told Sport Bible: “Here you have a guy that has made a career out of many years and that is Mayweather.
“And then you have the other guy that has made a career in a short time, but he made himself a big name.
“Me as a huge fan of the MMA, I see this fight. I don’t know. It can go both ways. Either what people predict that Mayweather will win easy, which I don’t believe.
“Conor has a power he can knock you out from every angle. And he has a confidence, like me.
“He is the Ibrahimovic of martial arts and I’m McGregor of the football world.
“So I see him with his confidence. He will win. Because he believes in himself so much and like I say, in everything you do the mental part is 50%.
“If you have the mental, the head, you can do it and achieve. And then at the same time he’s skilful, he is the one he is. So I believe in Conor!”