Floyd Mayweather's Vegas home was broken into this weekend while the boxer was in L.A. celebrating his 40th birthday ... and we're told thieves got away with $150k worth of stuff.
TMZ Sports has learned ... Mayweather is listed as the victim in a burglary report for a home he owns in a gated community next to a golf course.
Law enforcement sources tell us it appears someone forced a door open into the home office in the back of the house and stole several purses.
Other sources connected to the investigation tell us there is also at least 1 expensive watch unaccounted for ... and possibly other items missing.
Our law enforcement sources say cops have been in contact with Floyd's camp and the boxer has been instructed to take an inventory of his valuables.
Floyd was in L.A. for the past few days for his big 40th birthday mega-celebration with Justin Bieber, Mariah Carey and other famous friends.