From the MGM Grand to homes across America, boxing fans rained boos on Floyd Mayweather over the weekend — but the only sound the welterweight champ could hear was the ka-ching of cash registers.

With Saturday night’s fight making him the highest-paid champ in boxing history, Mayweather hardly seemed to notice he was also one of the most reviled.

“The check’s got nine figures on it, baby,” Mayweather bragged Sunday, as he waved the $100 million check he earned for beating Manny Pacquiao in a unanimous decision in Las Vegas.

“No pictures, though,” he warned reporters. “Don’t want any pictures of it.”

His total take could go as high as $180 million once pay-per-view revenue is tallied, experts said.

That would be by far the largest purse ever earned by a fighter.

But the welterweight title holder has also earned the ire of boxing fans, who are less impressed by his 48-0 record than they are repulsed by his constant bragging, his selfishness and his history of assaults on women.

Mayweather, who had a net worth of more than $300 million before the fight and the nickname “Money,” has gained a reputation for extreme greed.

Once he gave a radio interview in which he said people sometimes ask him why he hasn’t “given to Africa.”

“Well, what has Africa given to us?” he said.

“You hear people talking about, ‘Well he should give that to charity’ . . . No, I should donate to Floyd Mayweather.”

The fighter has also been accused of beating five women, including a 2010 attack on Josie Harris in front of their son, Koraun. He did two months in prison for the assault.

It was clear throughout the fight that the crowd was against him. The only time cheers rang through the celebrity-packed Las Vegas casino auditorium was when Pacquiao landed blows.

After winning, Mayweather jumped up onto the ropes and flexed his biceps for the crowd — which responded with vigorous boos.

He was later caught on a cellphone camera yelling at hecklers: “I told you so! I told you so!”

He admitted the crowd was against him, saying he was grateful the judges were not swayed.

“I know the judges weren’t going by the crowd screaming,” Mayweather said. “The judges were going by shots landed.”

Two judges scored it 116-112 for Mayweather, while a third judge had it 118-110.

After the fight, Mayweather took a pummeling on Twitter.

The Rev. Edward Beck, a Roman Catholic priest from New York, wrote: “Don’t understand how we make a serial batterer of women a national cultural hero. What does this say to our youth? #Mayweather is no winner.”

Despite the ill will for Mayweather, fans flocked to watch the fight. Total revenue for the event could top $400 million — most of it from almost $300 million in pay-per-view TV orders.

With demand so high, the fight was delayed by 30 minutes Saturday night as cable providers struggled to accommodate a flood of late orders.

Mayweather is contracted to get 60 percent of that TV pot.

Despite his disdain for charity, Mayweather spent the run-up to the fight bragging about what he would do to spread his wealth if he won — shower money on the strippers at Sin City’s finest gentlemen’s clubs.

Mayweather promised to party with a tote bag containing $250,000 cash, which would be carried by his crew — and be called the “pregnant duffel.”

The cash, he said, would be carried in five bundles of $50,000.

It wasn’t clear Sunday if he followed through with the plan, but it wouldn’t be such a far-fetched display of wealth for a fighter known to make seven-figure sports bets at Vegas casinos.