Laurel Wiig won a restraining order against Constance Meester, the actress' manager, after an ugly confrontation on January 21 in which she threatened to "hunt down and kill" and "f*ck up" the woman.
A Los Angeles judge ordered Constance, 55, to stay 100 yards away from Wiig.
"She is an addict and had made a threat to kill," Constance wrote in the court papers, obtained exclusively by Radar Online.
Constance gave birth to her daughter while doing time in a Texas prison after being nabbed in a drug ring, as the National Enquirer first revealed.
She was convicted in Georgia as part of an aunt's drug ring that smuggled thousands of pounds of marijuana from Jamaica to the United States.
Authorities said the operation netted $250 million a year.
Leighton's mom was sentenced to 10 years in prison and began serving time on August 8, 1985, while pregnant with the future TV star.
