Lee Byrne (Wales), Sergio Parisse (Italy) and Delon Armitage (England) are the other three players competing for the accolade.
All six were nominated by Team RBS, who together picked their top three players each (in order of preference) from the Championship in order to decide on the final six.
Former internationals Jason Leonard (England), Keith Wood (Ireland), David Sole (Scotland), Ieuan Evans (Wales), Philippe St Andre (France) and Alessandro Moscardi (Italy) based their decision on performance, form and achievement throughout this year's tournament.
Following his RBS Player of the Championship win last year, Shane Williams went on to amass a hoard of silverware, including the highly coveted IRB Player of the Year award.
Victory for this year's winners is sure to be a sign of great things to come, with an exciting summer of rugby up ahead.
The 2009 RBS Player of the Championship will be decided as a result of a public vote, hosted on www.rbs6nations.com.
Voting will continue through the final week of the Championship, and will close after the final round of matches, at 5pm on Monday, March 23.
Once the votes have been counted and verified, the announcement of the official RBS Player of the Championship will be issued during the following week.