Taking to social media on Wednesday, the singer shared a series of throwback photos of the mother-and-son duo as she confessed she was going to miss her firstborn when he leaves for America in the coming months.
WATCH: Louise Redknapp shares intimate look inside sun-soaked holiday
"To my big boy I can't put into words how much I love you, and how proud I am of you [heart emoji]," she wrote. "I can't believe this time 18 years ago you came into my world, you're my best friend, my rock and have been right by my side since the day you were born.
"You mean the world to me and I’ll be there too for you in this next chapter in life driving you mad being over protective and probably jumping on a plane every weekend to Arizona."
She added: "Enjoy your day and night, I'll allow you to make a mess in the kitchen today… just this once! My super star! Happy 18th Birthday Chaz… Love Mum Xxxx."
Louise shared a series of sweet snaps with her son Charley
Charley's dad Jamie also posted his own tribute, writing: "My big boy Charley is 18 today! I'm so proud of you mate and the man you've turned into. You are incredibly charming, funny, clever, kind and a superb athlete.
"Your next step in the US will be amazing and I can't wait to watch you every step of the way. I love you so much. Your Dad." His wife Frida commented: "Happy happy birthday @charley_redknapp!!!"
One of the images Jamie uploaded to mark Charley's birthday
Jamie and Louise are also parents to son Beau, 13. The former couple were married for 19 years before their divorce in December 2017.
The former footballer then tied the knot to Swedish model Frida in October 2021. They have since welcomed a little baby boy called Raphael. Frida, meanwhile, has four other children from her marriage to American hedge fund tycoon Jonathan Lourie.
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