Ronan Keating shares sweet message as he becomes a grandad aged 46

Ronan Keating has shared a sweet message on Instagram as he becomes a grandad at the age of 46.

Jack Keating took to social media yesterday (9 March) to make the surprise announcement that he has welcomed a baby girl.

The Love Island star, who appeared in Casa Amor in the eighth series of the ITV2 show last year, posted a black and white photo of him cradling his newborn.

In the caption of his Instagram post, Jack lovingly wrote, 'Welcome to the world my little princess’, with the girl in a tiara emoji.

Instagram/@jackkeating11

The post has been liked over 11,000 times and among the congratulations, many have taken to the comment section to point out that Jack was on Love Island just eight months ago.

"I’m so confused. The maths isn’t adding up," one follower said.

A second added: "I know I’m bad at maths, but the math ain’t mathing on this at all!!! Love Island isn’t even 9 months ago yet. I mean I know accidents happen but…"

And a third remarked: "Ok, I’m confused what? However congratulations I’m super happy for you."

Jack's mother and father were also quick to rush to the comment section to gush over their new granddaughter.

Boyzone's Ronan Keating wrote: "Little Cutie," while adding a heart emoji.

Jack's mum, Yvonne Connolly, added: "I miss her so much already," alongside several heart emojis.

Meanwhile, Jack's step-mum Storm, who has been married to Ronan since 2015, also shared some red heart emojis.

Instagram/@rokeating

Little is actually known about the baby, including her name and who the mother is.

But Jack has recently said that he is single, and although he may not have found love on Love Island, he hasn't given up hope.

Speaking to The Irish Independent earlier this month, he said: "I’m still single and ready to mingle.

"I’m on Hinge [the dating app], but I don’t use it too seriously. I dip in every once in a while and I’m enjoying being single."

But Jack's new life in the limelight has made it tricky for him in his quest for love.

"People think my account is fake," he said.

"I’m verified, but they still believe I’m a catfish who’s stolen someone else’s photos. I’m like: ‘Trust me - I’m the real deal'."

Jack will also appear in an episode of Dinner Dates, which will air on ITV later this month.