Collo – who has netted on 20 occasions so far this season – made the preliminary 38 man squad, which was narrowed down today to 23 players.
As a result, James will be unavailable for the Hatters' game against Doncaster Rovers on Saturday 23rd Match.
Ireland face Gibraltar that day, and then take on Georgia at home the following Tuesday.
A huge congratulations Collo!
Republic of Ireland Squad
Goalkeepers: Darren Randolph (Middlesbrough), Keiren Westwood (Sheffield Wednesday), Mark Travers (Bournemouth)
Defenders: Seamus Coleman (Everton), Matt Doherty (Wolverhampton Wanderers), Richard Keogh (Derby County), John Egan (Sheffield United), Shane Duffy (Brighton & Hove Albion), Enda Stevens (Sheffield United)
Midfielders: Alan Judge (Ipswich Town), Jeff Hendrick (Burnley), Conor Hourihane (Aston Villa), Alan Browne (Preston North End), Harry Arter (Cardiff City*), Glenn Whelan (Aston Villa), Robbie Brady (Burnley), Callum O'Dowda (Bristol City), James McClean (Stoke City)
Forwards: Shane Long (Southampton), Sean Maguire (Preston North End), Ronan Curtis (Portsmouth), David McGoldrick (Sheffield United), James Collins (Luton Town)
*Indicates player is on loan
EURO 2020 Qualifiers
March 23: Gibraltar v Republic of IrelandMarch 26: Republic of Ireland v Georgia