It was first reported in March that the Legally Blonde star was pregnant with her first child by second husband Jim Toth, but the blonde beauty kept mum about the rumours.
She let her body do the talking as she showed off her growing baby belly during a beach vacation in April - and Witherspoon has now talked openly about her latest pregnancy.
Speaking to a reporter after she was honoured with a special acting award in Chicago, Illinois on Saturday, the Chicago Sun-Times quotes the star as saying, "Frankly I'm feeling very round tonight. I'm always feeling like I'd like to eat everything in sight!"
Witherspoon said she is "very excited" about the new arrival, which is due later this year. The baby will be a sibling for the actress' two children by ex-husband Ryan Phillippe.