Prince William’s wife Catherine, Duchess of Cambridge, has given birth to a girl at St Mary’s Hospital in London.

Kensington Palace released a short statement via social media confirming the birth of the couple’s second child.

It said the Duchess, 33, gave birth to a girl weighing 8 pounds and 3 ounces.

The Duchess and her child are reportedly both doing well.

The couple’s first child, Prince George, was born in 2013 at the same hospital.

Catherine was admitted to St Mary’s Hospital in London in the early stages of labour.

Kensington Palace released a statement saying the Duchess travelled to the hospital in Paddington by car and was admitted at 6:00am local time (3:00pm AEST).

The couple’s first child, Prince George, was born in 2013 at the same hospital.

The baby will be fourth in line to the British throne behind brother George, father William and grandfather Prince Charles.

The couple shared the news on the official Kensington Palace Twitter account.

William will take two weeks of paternity leave from the training he is receiving for his new job as an air ambulance helicopter pilot.

He and Kate are planning to spend the first few days after the birth at their London residence, Kensington Palace, before travelling to Anmer Hall in Norfolk, a mansion on Queen Elizabeth II’s Sandringham estate where they have set up home.

Queen Elizabeth II, senior royals and Catherine’s parents, Michael and Carole Middleton, will be the first to be informed of the news.

It will then be announced both on the official Kensington Palace Twitter account and in the traditional way — with a royal bulletin displayed on an ornate easel in Buckingham Palace’s forecourt.

Cannons will be fired across London to celebrate the birth and the British flag will be flown from government buildings.

The baby’s gender is not known but bookmakers are tipping the child to be a girl, with Alice, Elizabeth, Charlotte and Victoria the favourite names.

James and Arthur are the favourite boys names.

The baby’s name may not be revealed for several days, William’s name was not announced for a week, while the world had to wait one month after his father Charles was born.

George’s name was revealed two days after his birth.

Crowds have been gathered outside St Mary’s Hospital in anticipation of the young royal’s birth for several days.

ABC/AFP