Cullen packs down in the second row alongside Damian Browne, while Jamie Heaslip will win his 50th Heineken Cup cap after being named in an all-Ireland international back row with Sean O'Brien and Rhys Ruddock.
Balbriggan's Jamie Hagan will make his Heineken Cup debut, starting in the front row alongside fellow 2007 Under-20 Grand Slam winning prop Cian Healy as well as the returning Richardt Strauss.
In the back-line, Isaac Boss partners Bank of Ireland Player of the Month Jonathan Sexton at half-back, with Eoin O'Malley coming in to partner Gordon D'Arcy in midfield and Fergus McFadden shifting to the wing.
Sean Cronin, who turned in an impressive performance against Glasgow Warriors, is one of five Ireland internationals named on the province's replacements bench.
Aside from the usual pre-match 'Family Day' activity around the ground, Leinster Rugby will welcome the Cavan RFC male voice choir to the RDS who will warm up the crowd pre-match.
Ashbourne RFC and Coolmine RFC will also perform in the half-time mini rugby exhibition. Gates open at 12pm and there will be no tickets on sale on the day.
With exams and a number of other events around the RDS on the day, fans are advised to arrive early and use public transport.
LEINSTER (v Montpellier): Rob Kearney; Fergus McFadden, Eoin O'Malley, Gordon D'Arcy, Isa Nacewa; Jonathan Sexton, Isaac Boss; Cian Healy, Richardt Strauss, Jamie Hagan, Leo Cullen (capt), Damian Browne, Rhys Ruddock, Sean O'Brien, Jamie Heaslip.
Replacements: Sean Cronin, Heinke Van Der Merwe, Mike Ross, Devin Toner, Shane Jennings, Eoin Reddan, Ian Madigan, Fionn Carr.