The fit-again Ireland winger joins Luke Fitzgerald and Isa Nacewa in the province's back-three for Sunday's game.
Eoin O'Malley partners Fergus McFadden at centre, with Isaac Boss linking up at half-back with Jonathan Sexton, one of Ireland's heroes against England.
Leo Cullen leads the team and starts from the second row alongside Devin Toner, and ex-Gonzaga College duo Kevin McLaughlin and Dominic Ryan join Rhys Ruddock in the back row.
Internationals Jamie Heaslip, Nathan Hines and Eoin Reddan have been selected on a strong replacements bench which features a mix of youth and experience.
Speaking ahead of the trip to Newport, Leinster skills and kicking coach Richie Murphy said that the players are expecting a tough battle with the Welsh regional side.
"A couple of the younger players have done well when they've played for the seniors. If you were to ask any of them I think they'd say that they have enjoyed their chances to play," he said.
"The senior guys that are there are looking after them and helping them through the games. And I think that the young lads are progressing well.
"Rodney Parade is a very difficult place to play. Over the last two years we have shipped reasonably big defeats, so I think this week it will be about us getting ourselves right, being mentally ready for the game and with the league position that we're in at the moment, it's a 'must win' game for us."
LEINSTER (v Newport Gwent Dragons): Isa Nacewa; Shane Horgan, Eoin O'Malley, Fergus McFadden, Luke Fitzgerald; Jonathan Sexton, Isaac Boss; Heinke van der Merwe, Richardt Strauss, Stan Wright, Leo Cullen (capt), Devin Toner, Kevin McLaughlin, Dominic Ryan, Rhys Ruddock.
Replacements: Aaron Dundon, Jack McGrath, Simon Shawe, Nathan Hines, Jamie Heaslip, Eoin Reddan, Ian Madigan, David Kearney.