03/14/2012 at 05:30 PM EDT
has joined the Hollywood mom's club!
, 36, "has adopted a child," her rep says in a statement to PEOPLE. "She is the proud mom of a healthy baby boy named Jackson."
Jackson is the first child for the South African-born Theron
, who recently starred in Young Adult
. She won an Oscar for her role as a serial killer in 2003's Monster
No further details about her new addition were released.
Though Theron is surely thrilled about expanding her family, she has previously spoken out about not feeling the need to tie the knot. Marriage, she said last year, was "never something that was important [to me]."
Reporting by ANNE MARIE CRUZ