Usain Bolt confirms he's having a baby girl with long-term partner Kasi Bennett

Usain Bolt has announced he will be a father to a baby daughter with girlfriend Kasi Bennett. [Courtesy]

Usain Bolt has announced he will be a father to a baby daughter with girlfriend Kasi Bennett.

The 100m world record holder, 33, who retired from the track in 2017, made the announcement at a gender reveal party on Monday.

The party, held at Peter's Rock in Kingston, Jamaica, featured a huge firework display and a celebrity guest list.

In a video on social media, Bolt said: "I just did the reveal and I'm a girl dad."

He went on to send a message to any future potential boyfriends, adding: "Any man, any boy, don't play with me!"

Bolt and Bennett have been together for six years with her identity kept quiet until towards the end of the sprinter's career.

The pair announced that they were expecting a child in January and were keen to shout about the gender this week.

The party featured pictures and video of the couple before a countdown preceded the big reveal and fireworks were let off.

Bolt attempted to keep his relationship under wrap for several years to keep his girlfriend out of the media.

The 100m world record holder made the announcement at a gender reveal party on Monday. [Courtesy]

In 2016, he said: "I'm not going to tell you who she is, I want to keep it small for now, because I know when it gets out there's going to be a lot of things to say, and I told her she can't handle it.

"Because I've been through the media. I understand how you guys are – especially the British media."