Joining O'Mahony are his fellow academy players Conor Murray and Andrew Burke who were both named in Munster's Magners League squad against Cardiff last weekend, with Burke receiving his first Munster cap.
It is not only academy players making the trip to Japan as three Munster Rugby sub academy players have also been selected for the squad. Garryowen's Ronan O'Mahony keeps his place after the 6 Nations tournament and will now be joined by UCC's David O'Callaghan and UL's Brian O'Hara.
Sub academy player David O'Callaghan was involved with the UCC side that won promotion to Division 1 and Brian O'Hara won an All Ireland U20 cup medal with UL Bohs.
The squad is built on the foundation of the U20 RBS 6 Nations Championship squad which saw Ireland finish in the runners up spot behind France who took the title on points difference. David O'Callaghan, Brian O'Hara and Nevin Spence all come into the squad, benefiting from their performances for the U20 Development team in their recent win against France in April in addition to Jonny Shiels who was capped for Ireland U19's last season.
Ireland has been placed in Pool A of the Junior World Championship which is taking place in Japan for the first time. Their opening three games see them play Argentina, defending Champions New Zealand and newcomers to the championship Uruguay.
The side will be captained again by No.8 Peter O'Mahony, who led the team during the U20 RBS 6 Nations Championship.
Andrew Burke (Garryowen/Munster)
Shane Gahan (Lansdowne /Leinster)
Matthew Healy (Lansdowne/Leinster)
David Kearney (Lansdowne/Leinster)
Michael Keating (Clontarf/Leinster)
Ian Madigan (Blackrock College/Leinster)
Ian McKinley (UCD/Leinster)
Conor Murray (Garryowen/Munster)
Ronan O'Mahony (Garryowen/Munster)
Eamonn Sheridan (Lansdowne/Leinster)
Jonny Shiels (QUB/Ulster)
Nevin Spence (Ballynahinch/Ulster)
Mark Flanagan (UCD/Leinster)
Adam Macklin (Belfast Harlequins/Ulster)
Paddy McAllister (Ballynahinch/Ulster)
Jack McGrath (St.Mary's College/Leinster)
David McGregor (Ballynahinch/Ulster)
Michael Noone (Seapoint/Leinster)
David O'Callaghan (UCC/Munster)
Jack O'Connell (Lansdowne/Leinster)
Brian O'Hara (U.L. Bohemians/Munster)
Peter O'Mahony (Cork Constitution/Munster) Captain
Rhys Ruddock (Millfield School/Exiles)
Ciaran Ruddock (Neath/Exiles)
Dominic Ryan (Lansdowne/Leinster)
Thomas Sexton (Old Belvedere/Leinster)
Allen Clarke - Coach
Philip Orr - Team Manager
Nigel Carolan - Assistant Coach
Colin McEntee - Assistant Coach
Emma Gallivan - Physiotherapist
Brian Devitt - Doctor
Philip Morrow - Fitness & Conditioning Coach
Vinny Hammond - Analyst
Regina Flanagan - Masseuse
Martin Joyce - Baggage Master
IRB Junior World Championship Pool A (all times are local)
05 Jun - 17:00 Argentina v Ireland Mizuho Rugby Ground, Nagoya
05 Jun - 19:00 New Zealand v Uruguay Mizuho Rugby Ground, Nagoya
09 Jun - 17:00 Argentina v Uruguay Mizuho Rugby Ground, Nagoya
09 Jun - 19:00 Ireland v New Zealand Mizuho Rugby Ground, Nagoya
13 Jun - 13:00 Ireland v Uruguay Mizuho Rugby Ground, Nagoya
13 Jun - 15:00 Argentina v New Zealand Mizuho Rugby Ground, Nagoya