Sporting couple Honor and Dan Carter have welcomed a third boy to their family.

The former All Blacks first-five eighth made the announcement on social media following the birth of Rocco Carter.

"Marco & Fox are proud new brothers We are excited to announce the arrival of Rocco George Carter, born 14th January. We are so grateful and couldn't be happier," Carter said.

The Carter family have been enjoying a New Zealand summer after the All Blacks great led his Kobe Steelers side to the Japanese Championship title.