Coleen Rooney has shared an adorable picture of her second son, Klay, to celebrate his first day at “big school”.

The proud mother-of-three joined a swathe of celebrities who gushed over their little ones as many began the new school year on Tuesday.

Rooney, 31, tweeted a snap of her four-year-old in his smart new uniform – complete with hat, tie and blazer – and wrote: “Big school for my gorgeous Klay!”

Britain’s Got Talent presenter Amanda Holden shared similar thoughts on her daughter Alexa on her first day in year one.

With a nostalgic black-and-white photo of her two daughters, she posted: “Big #school for my Lexi. #Hrh now year 1 #TimeFlies #sisters #SidebySide #TogetherStonger #love.”

Danielle Lloyd also shared news of her son George’s first day at school as well as a picture of all three of her boys in their matching uniforms.

George's first day at school can't believe my baby is all grown up 💙🌎😍

A post shared by Official Danielle Lloyd (@missdlloyd) on

Boys off to school looking all smart 💙🌎😍

A post shared by Official Danielle Lloyd (@missdlloyd) on

She wrote on Instagram: “George’s first day at school can’t believe my baby is all grown up.”

Meanwhile, Gogglebox star Scarlett Moffatt glowed with pride over her little sister’s first day in secondary school.

“Feels like yesterday my little sister was starting primary school eeek so grown up,” she wrote, and adding: “Good luck to her and everyone else starting secondary.”

While Michael Owen and Paddy McGuinness shared posts in anticipation of their own children returning to school tomorrow, TV survival expert Bear Grylls shared an inspirational message to all pupils across the country.

He wrote on Instagram: “Start of school for so many … it’s simple really, you don’t have to be the best or brightest, strongest or fittest, you just have to keep giving your all.

“Positivity and enthusiasm, courage and kindness, humility and respect to all. And then you are set to thrive in life. And that matters more than any school position! #nevergiveup.”