In an interview with NPR, the 44-year-old actress discussed the 1991 night when her mother, Gerda Maritz, killed her father, Charles Theron, in order to protect herself and her then-15-year-old daughter.
"My father was a very sick man," she said. "My father was an alcoholic all my life. I only knew him one way, and that was as an alcoholic."
Theron continued by explaining the situation with her dad was a "pretty hopeless" one that she and her mother were "just kind of stuck in."
"The day-to-day unpredictability of living with an addict is the thing that you sit with and have kind of embedded in your body for the rest of your life, more than just this one event of what happened one night," she said. "I think our family was an incredibly unhealthy one. And all of it, I think, scarred us in a way."
Though Theron said that she "of course" wishes that "what happened that night would have never happened," she also noted that "it's unfortunately what happens when you don't get to the root of these issues."
"My father was so drunk that he shouldn't have been able to walk when he came into the house with a gun," Theron recalled. "My mom and I were in my bedroom leaning against the door, because he was trying to push through the door. So both of us were leaning against the door from the inside to have him not be able to push through."
"He took a step back and just shot through the door three times," she continued. "None of those bullets ever hit us, which is just a miracle. But in self-defense, she ended the threat."
Though certainly a traumatic event in her life, Theron has made it a point to be open about her experience in order to help others.
"This family violence, this kind of violence that happens within the family, is something that I share with a lot of people," she said. "I'm not ashamed to talk about it, because I do think that the more we talk about these things, the more we realize we are not alone in any of it. I think, for me, it's just always been that this story really is about growing up with addicts and what that does to a person."
When it came time for her to start her own family, Theron "cast a very wide net" in her adoption search. That journey to become a single mom -- which ended with her adopting Jackson, 8, and August, 4 -- made her consider the "concept of what a family looks like" in a new way.
"In a lot of places -- and I think even for a lot of people and in America -- it still feels very traditional in the sense that it should be that every child should have a mother and a father," she said. "We've kind of wrapped our heads slowly around the idea of two mothers and two fathers, but not so much around the idea of a single parent. It's just so unfortunate."
Back in September, Theron opened up to ET about her family dynamic. Check out the exclusive, candid interview: