"To have one player from your squad nominated for an award like this would be a proud moment, but the fact that both Shane and Ryan are in contention should be looked on as a testament to the hard work and effort of the whole squad," said Gatland.
"Both have individual qualities, Shane Williams has been in sparkling form and not only lit up the 6 Nations but also shone on our tour to South Africa in the summer.
"Ryan returned from injury just before the 6 Nations to lead from the front and the leadership role he fulfils has been integral to our achievements and should not be underestimated.
"But to have two players recognised in the top five of the world game is the highest accolade and the nation, together with all of the Wales coaches and national squad, should take great pride in that fact."
The IRB Player of the Year award winner will be announced at the IRB Awards in association with Emirates Airline in London on November 23.
Scotland scrum half Mike Blair, New Zealand fly half and 2005 IRB Player of the Year Dan Carter and Italy captain Sergio Parisse join Wales pair Williams and Jones in being been nominated for the game's most prestigious award.
"The IRB Player of the Year Award is the ultimate accolade for a player and takes into account performances in all the major internationals played during the year including the RBS Six Nations, Tri Nations Series and the June-July tests," said International Rugby Board Chairman, Bernard Lapasset.
"The list of past winners of this coveted award is impressive and reads like a who's who of the international Game in recent years. Jonny Wilkinson, Schalk Burger, Richie McCaw, Fabien Galthie, Dan Carter, Keith Wood were all worthy recipients of the award, while Carter would be the first player to win twice should he be selected," added Lapasset.