Pictures: How the world is celebrating the royal baby
Messages of congratulations are coming in from around the world for William and Kate.
Blue lights illuminated the water in Niagara Falls on the American-Canadian border, to celebrate the birth of the Prince of Cambridge.
Prince William's football team Aston Villa have made this special HRH kit for the royal baby.
The Navy celebrated the news on board HMS Lancaster. They were on patrol in the Caribbean when they found out. The ships company spelt out the word BOY on the ships flight deck sending their best wishes and congratulations to the royal couple
London celebrated in style too! The London Eye was lit up in red, white and blue on the river Thames.
The British Telecom tower shouted "it's a boy" in lights at the top to mark the birth of a baby boy for Catherine, Duchess of Cambridge and her husband Prince William, in London July 23, 2013.
In Canada, they lit up their Peace Tower in Ottawa with blue lights. Kate and William's son was born at 4.24pm on Monday afternoon weighing 8 lbs and 6 oz.
In Stoke On Trent, these special mugs have been designed to celebrate the birth - but they're waiting for the announcement of the name!
In Tokyo, staff at Madame Tussauds have bought some balloons and put them next to the waxworks of Kate and William.
Christchurch Airport in New Zealand was also lit up in blue to celebrate the birth of the Prince of Cambridge.
Indian artist Sudarshan Pattnaik built this amazing sand castle to mark the birth of the royal baby on a beach in Puri, eastern India.
Celebrations are taking place all over the world after the birth of the Prince of Cambridge on Monday. Here, the King's Troop Royal Horse Artillery fire a 41 Gun Royal Salute to mark the birth of the royal baby, in London's Green Park on Tuesday afternoon.