Floyd Mayweather's Ex Josie Harris Death Ruled Accidental, 'She Will Be Missed'

Josie Harris -- Floyd Mayweather's ex -- died from the result of an accidental overdose of Rx medication, TMZ Sports has learned.

We broke the story, Harris was found unresponsive in her car in front of her Valencia, Calif. family home back in March.

We were told despite lifesaving efforts from emergency personnel ... Harris passed away on the scene at 40 years old.

An autopsy was conducted, which included toxicology, and we're told the family has now been informed the official cause of death is listed as an accidental overdose.

We spoke with Josie's attorney, Dan Friedlander, who issued a statement on behalf of the family.

"The family is aware the medical examiner has released the report and they are thankful for the closure. Josie will be remembered as a truly kind and giving person and loving mother. She was loved and will be missed."

Floyd dated Harris in a famously up-and-down relationship from 1995 until 2010 ... and after her death, he called her "a great woman" and "a great person."

As we previously reported, Floyd was so rocked by the passing of Josie, as well as his Uncle, Roger Mayweather, he decided against making a return to the pro boxing ring in 2020.