The little four-year-old was snapped looking very smart in his brand new school uniform – a blue and yellow striped blazer and matching cap, a tie, shirt and jumper, grey shorts, long socks and shiny black shoes.
Proud Coleen Rooney has shared a photo of Kai on his first day at school
Like so many other parents whose children will be starting school this week, Coleen wanted to capture the momentous occasion, and shared the picture with her Twitter followers, captioning the photo, "Kai looking smart on his 1st day at school!!"
Kai and his little brother Klay, 15 months, recently returned from a holiday in Cyprus with Coleen and her parents, Tony and Colette.
Coleen Rooney with her sons Kai and Klay
There was cause for further celebration earlier in the week, when dad Wayne Rooney was named captain of the England football team.
Confirming his appointment on Tuesday, Wayne, 28, tweeted, "Being named England captain is a dream and something I'll take great pride in doing."
Delighted Coleen, 28, showed her support for her husband, writing on her page, "Fantastic news!!! Captain of our country!! So proud!!"