The sports star was arrested in September, 2010 after Josie Harris accused him of striking her "multiple times in the head with his fist" and allegedly threatening to beat up their two children, who at the time were aged nine and 10.
On Wednesday (21Dec11), the athlete struck a plea deal with prosecutors to escape a felony battery charge and pleaded guilty to a lesser count of misdemeanour domestic violence. He also pleaded no contest to two misdemeanour harassment charges.
Las Vegas Justice of the Peace Melissa Saragosa then handed Mayweather, Jr. a three-month jail sentence and ordered him to complete 100 hours of community service, enrol in a 12-month domestic violence programme and pay a $2,500 (£1,560) fine.
If he fails to obey to the terms of the agreement, the boxer will be forced to serve another three months behind bars.
Mayweather, Jr. must turn himself into Sin City's Clark County Detention Center on 6 January (12).
Three days will be deducted from his total sentence for time served, reports TMZ.com.