Joanna Page is expecting her third child with husband James Thornton.
The 38-year-old 'Gavin & Stacey' actress made the announcement via Twitter and said that morning sickness has been a "breeze" compared to looking after her two children, three-year-old daughter Eva and son Kit.
She wrote: "Some good news! We've got baby number 3 on the way!!!! ... Morning sickness is a breeze when you're already looking after a 3 and 1 year old!" (sic)"
Meanwhile, her 'Emmerdale' actor husband also confirmed the happy news.
He wrote: "Great news! Baby number 3 is on the way! Gonna be shifting from man to man marking to more of a zonal system of child control! (sic)"
Joanna has previously confessed that she is "addicted" to adding to her brood.
She said: "James is one of four, so to him four is the norm. For me one is the norm, but I can see how people get addicted to having babies.
"I would like to keep going and pop out as many as possible - I only wish I'd started having them at a younger age."
And she also admitted she is quite a strict parent and that she will turn the radio off if they hear explicit lyrics, as having Eva has made her more "responsible".
She previously said: "So many more things are important because they learn from what they watch.
"I know I sound like a really boring mum but every song you hear on the radio is about sex or not respecting yourself.
"There might be a song that I love to sing myself but I can't play it in front of Eva. She's brought out my responsible side."