Wales star North to retire from Test rugby after Italy Six Nations clash
North, who has won 120 caps, said on X, formerly known as Twitter, that it was the "right to time step away".
The 31-year-old, who has been recalled to the starting side for the clash in Cardiff, is second on Wales's all-time list of try-scorers with 47, behind Shane Williams (58).
"I've decided that the game on Saturday will bring my international career to an end," said North, now playing club rugby for Welsh regional side Ospreys.
"After 14 years it feels like now is the right time to step away. I have loved and cherished every second in a Welsh shirt and been able to play alongside some fantastic team-mates."
He added: "I've been very lucky to have lived my dream. I'm excited for the next chapter."
The England-born back scored two tries on his Wales debut as an 18-year-old wing against South Africa, after making his name with the Llanelli-based Scarlets.
Wales coach Warren Gatland, who gave North his international debut in his first spell in charge of the national side, paid tribute.
"George has contributed hugely to Welsh rugby in an incredible career, starting as an 18-year-old," he said.
"The way that he burst onto the scene... I can remember seeing him play and thinking we need to cap this kid.
"He's been incredible as a rugby player, but I think the most important thing is how he's contributed to the squad as a person over the years."
'Outstanding'
The New Zealander added: "George has been outstanding and a credit to himself. He can definitely hold his head high. He and his family and friends can be very proud of everything he has achieved.
"I look forward to watching George play at Principality Stadium one final time in a red jersey on Saturday, and I hope everyone will join me in celebrating him."
Powerhouse flyer North toured Australia with the British and Irish Lions in 2013 and represented the combined side again in New Zealand four years later.
He also helped Wales win Six Nations Grand Slams in 2012 and 2019, as well as the 2013 and 2021 Six Nations titles, while last year he appeared in a fourth World Cup.
But North will end his international career by trying to help Wales avoid losing all five games in a single Six Nations campaign for the first time since 2003.
The team have lost 11 of their past 12 matches in the competition.
North and fellow centre Nick Tompkins, neither of whom featured in last week's 45-24 defeat by France in Cardiff, replace Joe Roberts and Owen Watkin in the starting side announced by Gatland on Wednesday.
Gatland has also made changes to the Welsh pack, with Harlequins prop Dillon Lewis preferred to Keiron Assiratti and Cardiff flanker Alex Mann recalled to the back row.
Wales captain Dafydd Jenkins, who featured at blindside flanker against France, returns to the second row alongside Adam Beard, with Will Rowlands dropping to the bench.
Italy will kick off in Cardiff buoyed by a 31-29 win over Scotland in Rome, which followed a morale-boosting 13-13 draw with France.
The Azzurri will also be looking for a second straight win in the Welsh capital following a thrilling 22-21 Six Nations success two years ago.
"We definitely don't want to finish bottom and the squad is hungry to win," said Gatland.
"Italy have quality players throughout the side and have been good at taking opportunities when they get them to keep the scoreboard ticking over. We're excited and will step up and welcome the challenge ahead."