The most likely baby names for Kate Middleton and Prince William's third child

The Duke and Duchess of Cambridge have welcomed their third child, a boy - and some new frontrunners have emerged in the name predictions.

Ever since we got word from Kensington Palace that another royal baby was on the way, bookies have been taking bets on what the young prince, who will become fifth-in-line to the throne, will be called.

RELATED: Kate Middleton gives birth to baby boy

For UK betting company Ladbrokes, the odds have changed dramatically in the hours since the baby was born.

Speaking to 9Honey outside the Lindo Wing of St Mary's Hospital in London - where the Duchess of Cambridge gave birth - a spokesperson named Alex said a betting frenzy had resulted in clear favourites.

The top four names are currently Arthur (7-4), James (3-1), Albert (4-1) and Philip (5-1), but that could continue to change.

"All of those have seen their odds change quite drastically," he explained.

"James was a 10-1 shot when I woke up this morning, it's been slashed to 3-1."

WATCH: Prince George and Princess Charlotte arrive at St Mary's Hospital to meet their new baby brother. (Post continues.)

Sportsbet.com.au currently has the same four favourites, but in a slightly different order: Arthur, Philip, James and Albert.

Prior to Kate Middleton giving birth, and before we knew for sure it was a boy, there was speculation royal baby number three would be named after the late Princess Diana. 

But 9Honey royal correspondent, Victoria Arbiter, insisted Kate and Will would stick to a traditional moniker -- whether it was a prince or princess.  

"I think we'll see something traditional like George and Charlotte, but there is a little bit more leeway given this baby is number three," Victoria previously explained.

"So, the frontrunners at the moment are Alice for a girl, which would be in tribute to Prince Philip's mother, and Arthur for a boy -- the middle name of William." 

Both William and Kate by nature are very traditional, Victoria explained, so it is more than likely they'll take their pick of names from the Royal Family tree. 

With the royal baby officially here, and Meghan Markle's wedding to Prince Harry in mere weeks, it's going to be a busy few months at Buckingham Palace!

9Honey is on the scene outside St. Mary’s Hospital in London — check back often for ongoing updates — and be sure to follow 9Honey on Instagram for all things royal baby!