The 28-year-old centre has shown encouraging progress and will be competing with Luke Fitzgerald for the chance to partner Brian O'Driscoll in midfield.
D'Arcy, player of the tournament for the 2004 and 2007 Six Nations, missed the autumn internationals as he continued his rehabilitation from injury.
Elsewhere, there was little scope for controversy as Ireland head coach Declan Kidney named a large 39-squad that covered all bases.
Seven uncapped players - Cian Healy, Darren Cave, Ryan Caldwell, Ian Dowling, Jonathan Sexton, Tom Court and Mike Ross - have been included.
Ulster centre Cave features in a senior Ireland squad for the first time.
Leo Cullen, Tony Buckley, Neil Best and Roger Wilson were not considered for selection due to injury or suspension.
Kidney said: "We want to continue to develop a panel and bringing in 39 players allows to us to work with the players on this basis.
"As well as bringing the players through the systems of the team, it allows for the usual knocks the players might pick up.
"The core group of players who were part of the November squad have maintained their form.
"But it's also pleasing to be able to bring in players who are really developing this season like Darren Cave and Tom Court.
"The more established players have also performed well over the last number of weeks."
Ireland Squad for RBS 6 Nations Championship:
Backs: Tommy Bowe (Ospreys), Ian Dowling (Munster), Girvan Dempsey (Leinster), Darren Cave (Ulster), Gordon D'Arcy (Leinster), Keith Earls (Munster), Luke Fitzgerald (Leinster), Shane Horgan (Leinster), Robert Kearney (Leinster), Geordan Murphy (Leicester), Brian O'Driscoll (Leinster), Ronan O'Gara (Munster), Tomas O'Leary (Munster), Eoin Reddan (Wasps), Jonathan Sexton (Leinster), Peter Stringer (Munster), Andrew Trimble (Ulster), Paddy Wallace (Ulster).
Forwards: Rory Best (Ulster), Ryan Caldwell (Ulster), Bob Casey (London Irish), Tom Court (Ulster), Stephen Ferris (Ulster), Jerry Flannery (Munster), John Hayes (Munster), Cian Healy (Leinster), Jamie Heaslip (Leinster), Marcus Horan (Munster), Bernard Jackman (Leinster), Shane Jennings (Leinster), Denis Leamy (Munster), Donncha O'Callaghan (Munster), Paul O'Connell (Munster), Mick O'Driscoll (Munster), Malcolm O'Kelly (Leinster), Alan Quinlan (Munster), Mike Ross (Harlequins), Donnacha Ryan (Munster), David Wallace (Munster).