Mayweather, 33, was booked Friday on a grand larceny charge at the Clark County jail and held on $3,000 bail, Las Vegas police Officer Bill Cassell said.
Mayweather's lawyer, Richard Wright, said Mayweather is accused of taking an iPhone from Josie Harris, his ex-girlfriend and mother of three of his children.
"He surrendered," Wright said, denying the allegations against Mayweather.
"He did not commit any grand larceny," Wright told The Associated Press. "Josie can't find her iPhone. We're attempting to find it or replace it. We'll cooperate in the investigation. We expect to get the matter resolved."
Harris made a police complaint and sought a Family Court protection order Thursday alleging Mayweather pulled her hair, punched her in the head and twisted her arm while she screamed for their children, ranging in age from 7 to almost 11, to call 911.
Police said Thursday that Harris was treated at a Las Vegas hospital for minor injuries.
"Please order Floyd Mayweather to not try and contact me," Harris wrote in an application for a protection order that said the couple separated in May after living together for seven years.
"Floyd has threatened to have other people do harm to me as well and if (there) is a way I can be protected from that please help me," the document says.
Mayweather is undefeated as a professional fighter and is considered one of the sport's top performers, with a record of 41-0 and 25 knockouts. He goes by the nickname "Money" and earned more than $20 million in May from his fight in Las Vegas against "Sugar" Shane Mosley.
Mayweather has also been arrested several times over the years on battery and assault allegations.
He was acquitted by a Nevada jury in July 2005 after being accused of hitting and kicking Harris during an argument outside a Las Vegas nightclub.
Harris, then 25, recanted her allegations and testified that she lied to police because she was angry Mayweather left her for another woman.