By TMZ Sports

Floyd Mayweather's ex-girlfriend is FURIOUS at Conor McGregor over a "trolling" stunt that mocked her domestic violence incident with Floyd ... saying he's shamelessly profiting from her pain.

The woman is Josie Harris -- who Floyd was convicted of attacking during a 2010 domestic violence incident at her Vegas home in front of their 3 kids. Mayweather spent 2 months behind bars for the attack.

McGregor "trolled" Floyd over the incident last week by wearing an NBA jersey of C.J. Watson -- the man Floyd accused Josie of secretly texting in 2010, which led to the violent altercation.

Josie wasn't laughing when she saw Conor's stunt -- and claims McGregor's doing nothing more than exploiting her trauma to promote his superfight with Floyd on August 26th at the T-Mobile Arena in Las Vegas.

"Conor McGregor's exploitation of the events surrounding Mayweather's violent beating of Josie Harris, for the sole purpose of promoting an upcoming boxing match and taunting his opponent in the ongoing media-driven feud between the two fighters, demonstrates not only an insensitivity toward the emotional well-being and privacy of the victim of Mayweather's domestic violence, but also a general disregard for the physical and emotional trauma and long-lasting psychological impacts suffered by victims of domestic abuse," Josie's attorney, Dan Friedlander, tells TMZ Sports.

"In the aftermath of the events of September 9, 2010, Josie Harris, like many of the victims of domestic violence, continues to endure the emotional and psychological trauma, shaming, humiliation, blaming and embarrassment caused by Mayweather's violence and further perpetuated by his continued public denials, disclaimers, excuses and deferrals of responsibility of his actions, including Mayweather's defamatory statements made against Harris made during 2015 interview with Katie Couric leading up to his fight with Manny Pacquiao.

"Although McGregor played no part in Mayweather's physical and emotional abuse of Harris, his exploitation of the events of September 9, 2010, for publicity, entertainment, and personal gain, demonstrates a lack of sensitivity toward Harris and her three children who witnessed Maywetaher's violence and the trauma they have suffered, and continue to suffer as a result of Mayweather's conduct.

By sensationalizing Mayweather's past acts of domestic violence to create entertainment and promotional value, McGreger trivializes domestic violence in disregard for the privacy and well-being of those who have suffered at the hands of an abusers, further compounding the emotional and psychological trauma, shaming, humiliation, blaming, and embarrassment suffered by so many victims."