The pair missed the draw with France last time out, while Sexton was also sidelined for the defeat to Scotland on February 24.
Sexton's absence was due to a hamstring complaint picked up early on in the Round 2 loss to England, with Gilroy damage his groin at Murrayfield a fortnight later.
The favourite for the Lions No10 shirt suffered a minor scare when he rolled his foot in training this morning but Ireland coach Declan Kidney insists his star playmaker will be fully fit for the trip to the Stadio Olimpico.
"Jonny turned over on his foot a little bit this morning, but we expect that he'll be fine," said Kidney.
"He's being checked out now. Ian Madigan will travel with us as cover.
"Jonny's very keen to get going now and is very happy to be involved."
Kidney makes two more change to his replacements' bench as Leinster lock Devin Toner comes in for double Lions tourist Donncha O'Callagahn and Ulster's Paul Marshall steps in for Eoin Reddan after the back-up scrum-half broke his leg last time out.
Ireland have never lost to Italy in the Championship but a first defeat to the Azzurri since 1997 would leave them in contention for the Wooden Spoon.
A third win of the tournament would secure a third-place finish, though, if France also see off Scotland in Paris on Saturday evening.
The match could be legendary centre Brian O'Driscoll's last in the Championship, although the 33-year-old is yet to make an announcement on his potential retirement from international rugby.
Ireland (versus Italy, Stadio Olimpico, Saturday 2.30pm)
Rob Kearney (Leinster); Craig Gilroy (Ulster), Brian O'Driscoll (Leinster), Luke Marshall (Ulster), Keith Earls (Munster), Jonathan Sexton (Leinster), Conor Murray (Munster); Cian Healy (Leinster), Rory Best (Ulster), Mike Ross (Leinster), Mike McCarthy (Connacht), Donnacha Ryan (Munster), Peter O'Mahony (Munster), Sean O'Brien (Leinster), Jamie Heaslip (Leinster, captain)
Replacements: Sean Cronin (Leinster), David Kilcoyne (Munster), Stephen Archer (Munster), Devin Toner (Leinster), Iain Henderson (Ulster), Paul Marshall (Ulster), Paddy Jackson (Ulster), Luke Fitzgerald (Leinster)