The Newtownmountkennedy second row joins fellow Ireland internationals Shane Jennings, Malcolm O'Kelly and Mike Ross in the pack alongside Rhys Ruddock who makes his second appearance for the province, and his home debut, after leading the Ireland Under-20s to the Six Nations title last weekend.
Eoin Reddan links up at half-back with Jonathan Sexton, with Shaun Berne shifting to inside centre.
Girvan Dempsey, a try scorer in the 20-14 victory over the Glasgow Warriors last time out, starts on the right wing to accommodate the return of Rob Kearney from international duty.
Kearney starts at full-back with Isa Nacewa continuing on the left wing.
Over 13,500 tickets have now been sold for Saturday's interprovincial game. The remaining tickets are on sale on www.leinsterrugby.ie and are also available from Spar (Donnybrook), the Leinster Rugby Store (Donnybrook) and Ticketmaster outlets nationwide.
Speaking ahead of the game, Leinster coach Michael Cheika said: "This period of the calendar is always a bit difficult to manage but it's a good time to test the strength of our squad.
"We also have an extra game in there because of the postponements in January, so that meant there was an extra workload, but hopefully our results in this period are an indicator as to how we might perform over the next few weeks.
"There was a pretty poignant time last year when we lost to Connacht. Their coach (Michael Bradley) said in the aftermath that they targeted us.
"Obviously they think that they can beat us and they feel that they have the wood over us, or the better of us.
"Home matches are very important for us and Saturday is going to be a big game. Every match against Connacht over the last five years has been a battle so we have to make sure that we're strategically right and physically right particularly."
LEINSTER (v Connacht): Rob Kearney; Girvan Dempsey, Fergus McFadden, Shaun Berne, Isa Nacewa; Jonathan Sexton, Eoin Reddan; Stan Wright, John Fogarty, Mike Ross, Leo Cullen (capt), Malcolm O'Kelly, Rhys Ruddock, Shane Jennings, Stephen Keogh.
Replacements: Bernard Jackman, CJ van der Linde, Devin Toner, Paul Ryan, Paul O'Donohoe, Eoin O'Malley, Simon Keogh.