Prince William, who is Vice Royal Patron of the Welsh Rugby Union, will attend the game at the Millennium Stadium and present the RBS 6 Nations trophy to the championship winner.
Wales, unbeaten to date in the championship, will win the title if they beat France – or lose by fewer than 20 points.
WRU Chairman David Pickering said: “We are delighted that Prince William will be at the Millennium Stadium on Saturday to share what I am sure will be a very special day for Welsh rugby.
“He has taken time out of an extremely busy schedule and we are delighted that he will present the RBS 6 Nations Trophy to the tournament winner.”
This will be the fourth Wales match Prince William has attended at the Millennium Stadium since he took up the role in February 2007.
