According to Life And Style Weekly magazine, the Oscar-winning actress is three months pregnant with her second child with Canadian model Gabriel Aubry.
"Halle is overjoyed. She's just ecstatic to be pregnant again. She wasn't sure if she'd have another baby, so she's very happy," a source tells the magazine.
Her spokesperson is yet to comment on the reports, however.
The 43-year-old has admitted she found it hard to get pregnant with her first baby, daughter Nahla Ariela, now 17 months – suffering through 30 negative pregnancy tests before she finally got the result she wanted.
This time around the baby is reported to have been conceived by artificial insemination.
When pregnant with Nahla, Halle revealed she and Gabriel were keen to have at least two children.
"We always talked about having two," she said. "Whether or not we'll actually make that happen is left to be seen, but that would be our intent. That's for sure."