Former Olympic champion Libby Trickett and husband Luke have welcomed a son.

The 38-year-old swimmer announced the happy news to her social media on Friday.

‘He’s here,’ the proud mum gushed in her post. ‘The final little piece to our family puzzle (for reals this time!),’ she continued.

‘Alfred Sunny Trickett arrived at 9.09am on the 17th of May Every birth I’ve had has been extraordinary and this one was no different. 

‘Calm, full of joy and laughter, I couldn’t have asked for a better way to meet our baby boy.’

Former Olympic champ Libby Trickett and husband Luke welcomed a son, Alfie Sunny on Wednesday – all pictured

The gold medal winner said that Alfie arrived into the world via elective caesarean birth, weighing 3.5kg and measuring 52cm long

Libby included an intimate photo in her story.

A smiling Libby can be seen holding her new born to her chest, soon after giving birth, while husband Luke poses beside her.

Already a mother to three girls, the champion swimmer joked: ‘Alfie has no idea what he’s in for with his three big sisters and the girls are absolutely smitten.’

The gold medal winner said that Alfie arrived into the world via elective caesarean birth, weighing 3.5kg and measured 52cm long.

Libby and Luke already share three daughters Poppy, seven, Edwina, four, and Bronte, two – all pictured. The champion swimmer joked: ‘Alfie has no idea what he’s in for with his three big sisters and the girls are absolutely smitten,’ she said

It comes after Libby had announced that she wanted to keep the sex of her new born a secret

It comes after Libby had announced that she wanted to keep the sex of her new born a secret.

‘It will be a surprise,’ she said during an appearance on Channel Seven’s The Morning Show in December.

Libby and Luke already share three daughters Poppy, seven, Edwina, four, and Bronte, two. 

Libby, who was once the fastest female swimmers in the world, was forced to give up on her career in the pool at just 28 due to injury. 

Libby, who was once the fastest female swimmers in the world, was forced to give up on her career in the pool at just 28 due to injury