The 36-year-old adopted six month old Jackson in March and says her son has given a new direction to her life, reported Ace Showbiz.
"When I first heard my son was coming into my life, I didn't want to make the film. But having him has changed me and made me a lot more creative as a person," Theron said.
The "Monster" star has been single since her nine-year-old relationship with Irish actor Stuart Townsend ended in 2010.
"You know, I don't think any mother aims to be a single mom. I didn't wish for that, but it happened. I always knew, I would adopt. Always," she said.
Theron, who was last seen 2011 movie "Young Adult", will be next seen as the evil queen Revenna in "The Snow White and the Huntsman".