"I'm completely in awe of his incredible mother and how she has been the whole way through this, she's really made my dreams come true. We haven't named him yet but he's already capturing hearts including mine. I feel very blessed. Happy Mother's Day everyone!"
Cheryl, 33, also shared the picture, revealing that the tot was born three days previously.
She wrote: "On Wednesday 22nd March Liam and I became parents to an incredibly beautiful, healthy baby boy, weighing 7lb 9 and looking like a dream. Although he still doesn't have a name he is already stealing hearts.
"We are all madly in love and overwhelmingly happy with our little arrival. Happy Mother's Day to all the mothers around the world. A day that now has a different meaning to me forever (sic)."
Liam, 23, recently gushed about his "dream girl" Cheryl and said this is a "precious time" for them both.
He said: "This is the thing. In a non-cliché way, it's weird waking up every day and literally living out your dream. You wake up in the most beautiful places.
"Obviously I have the most beautiful girlfriend in the world and she's absolutely amazing. She's been my dream girl since I was younger. She's so ace. We're super happy. It's a very personal, precious time for us."
