Simon, who plays soap favourite Steve McDonald, announced the happy news via Twitter last night with a hilarious photo.
Choosing to announce his baby news on the social networking site, Simon shared an image of him having a "beer" belly and Emma with a "baby" belly.
He captioned the snap: "After a stressful few months.... Myself and @emmagleave are excited to announce...."
Simon and Emma are already parents to young sons Harry and Alfie.
Simon's co-stars sent their congratulations after seeing the funny picture. Samia Ghadie, who is currently expecting her second child, tweeted: "@simongregson123 @emmagleave aw brilliant!! So happy for u monkeys! #babyboom xxx."
And Reveal's blogger Brooke Vincent, said: "Omfg!!!!!!!! CONGRATULATIONS @simongregson123 @emmagleave I'll drink for you Em don't worry!!"
For exclusive competitions and amazing prizes visit Reveal's Facebook page NOW!
More stars who have announced baby news this year:
Copyright: Instagram @fearnecotton4