The royal couple appeared happy and relaxed as they waved at the crowds of journalists and onlookers gathered outside London's St. Mary's Hospital, posing for photographs and joking with reporters.
"It's very emotional. It's such a special time. I think any parent will know what this feeling feels like," she told journalists.
She then gave the baby to her husband, who, cradling their child, said: "He's got her looks, thankfully. He's got a good pair of lungs on him, that's for sure."
William added: "He's a big boy. He's quite heavy," and laughed when a reporter asked him about the baby's hair.
"He's got way more than me, thank God," he said.
The prince said they are still determining what to name the baby.
The couple re-entered the hospital to place the child in a car seat before re-emerging to get into an SUV. William drove the couple away- palace officials said they will head to an apartment in Kensington Palace.