In an interview with Elle magazine, the "Atomic Blonde" actor, who was born and raised in South Africa during the apartheid, talked about the prevalent social climate and raising two black children in the US.
The actor said she would not consider taking up jobs in certain areas of the country over fears for her family and how they would be treated.
"Racism is much more alive and well than people thought. We can't deny it anymore. We have to be vocal. There are places in this country where, if I got a job, I wouldn't take it. I wouldn't travel with my kids to some parts of America, and that's really problematic," Theron said.
"There are a lot of times when I look at my kids and I'm like, If this continues, I might have to (leave America). Because the last thing I want is for my children to feel unsafe.
"I want them to know who they are, and I want them to be so f**king proud of who they are. Building confidence for them right now is an oath I made to myself when I brought them home. They need to know where they come from and be proud of that.
"But they're going to have to know that it's a different climate for them than it is for me, and how unfair that is. If I can do something about that, of course I'm going to," Theron said.
Theron will be next seen in comedy-drama "Tully", where she reunited with her "Young Adult" director Jason Reitman and screenwriter Diablo Cody. She plays a mother in the film who develops a friendship with her babysitter.