Johnny Sexton will succeed Rory Best as Ireland captain after being chosen to lead Andy Farrell's first squad.
The Leinster fly-half is a doubt for the start of the Six Nations having picked up a knee injury last month but is still named in the 35-man squad.
Ulster backs John Cooney and Billy Burns have been rewarded for their impressive form, but Stuart McCloskey misses out.
Lock Devin Toner is also included after his Rugby World Cup squad omission.
Sexton, 34, captained Ireland from the start for the first time against Russia at the World Cup, but has long since held a leadership role within the squad.
With 88 international caps, prop Cian Healy (95) is the only player in the squad to have made more appearances than the new skipper.
With Joey Carbery's injury and Jack Carty's exclusion, Ross Byrne and Burns, uncapped at international level, will jostle for the back-up fly-half spot and could find themselves starting against Scotland on 1 February if Sexton is unable to prove his fitness.
Another big call facing Farrell is at scrum-half, where Cooney's scintillating form at number nine could see him challenge the established Conor Murray for the starting place.
Having failed to cement himself in former head coach Joe Schmidt's plans, Farrell's first squad announcement brings more disappointment for centre McCloskey who was hopeful of a call-up following some impressive club form.
Jacob Stockdale will compete for a starting berth on the wings with Munster duo Andrew Conway and Keith Earls while Jordan Larmour and Will Addison, both enjoying strong seasons for their provinces, are the contenders for the full-back jersey in the absence of Rob Kearney.
Kearney, 33, was omitted from Farrell's pre-Christmas training squad, although brother Dave does make it having scored nine tries for Leinster this season.
Along with Rob Kearney, Jordi Murphy, Sean Cronin, Jack Carty and Kieran Marmion have also failed to make the cut, while John Ryan and Tadhg Beirne are absent.
Fronting up
Former captain Best's retirement has opened up plenty of competition for the hooker's starting jersey, with Niall Scannell holding the role of replacement hooker during the World Cup.
However, Munster's Scannell is not named in Farrell's squad, which means Ulster's Rob Herring will battle with Dave Heffernan and Leinster youngster Ronan Kelleher for the starting spot.
Ulster's Tom O'Toole is a surprise selection among the front row forwards, and the contingent from the northern province reflects the province's strong start to the campaign.
Farrell finds a place for 33-year-old lock Toner, while Jean Kleyn misses out. The former's omission from last year's World Cup squad in favour of the South African-born Kleyn one of the most hotly-debated decisions of the Schmidt era.
There are several new faces in the back row, with a number of youngsters called into the fold.
Highly-rated Max Deegan is set to make his senior bow along with Leinster team-mate Caelan Doris, who have impressed for Leo Cullen's men this season, while Jack O'Donoghe will hope to add to his two international caps.
Ireland welcome Scotland to the Aviva Stadium for their opening Six Nations encounter on 1 February.
Wales travel to Dublin the following week, before a trip to Twickenham to face England with games at home to Italy and away to France rounding out Farrell's maiden campaign.
Ireland's Six Nations squad:
Hooker: Rob Herring (Ulster), Ronan Kelleher (Leinster), Dave Heffernan (Connacht)
Prop: Cian Healy (Leinster), Dave Kilcoyne (Munster), Tadhg Furlong (Leinster), Andrew Porter (Leinster), Tom O'Toole (Ulster), Jack McGrath (Ulster)
Lock: James Ryan (Leinster), Iain Henderson (Ulster), Devin Toner (Leinster), Ultan Dillane (Connacht)
Back row: Peter O'Mahony (Munster), Josh van der Flier (Leinster), CJ Stander (Munster), Max Deegan (Leinster), Caelan Doris (Leinster), Jack O'Donoghue (Munster)
Scrum-half: Conor Murray (Munster), John Cooney (Ulster), Luke McGrath (Leinster)
Fly-half: Johnny Sexton (Leinster), Ross Byrne (Leinster), Billy Burns (Ulster)
Centre: Bundee Aki (Connacht), Robbie Henshaw (Leinster), Garry Ringrose (Leinster), Chris Farrell (Munster)
Wing: Jacob Stockdale (Ulster), Andrew Conway (Munster), Keith Earls (Munster), Dave Kearney (Leinster)
Full-back: Jordan Larmour (Leinster), Will Addison (Ulster)