Seven of the squad featured in the 2011 IRB Junior World Championship. Flankers Shane Buckley and Aaron Conneely, second row Iain Henderson and prop Tadhg Furlong will add experience up front.
In the back-line, Mike Ruddock can call upon the experience of Paddy Jackson, who recently starred in Ulster's Heineken Cup semi-final win, JJ Hanrahan and scrum half Kieran Marmion who all featured in last year's tournament.
Ireland Under-20 head coach Ruddock said: "We are coming into the IRB Junior World Championship on the back of a relatively successful Six Nations having won four out of five of our matches.
"This gives us some confidence going into the tournament. However, we are in an extremely physical group.
"We have hosts South Africa up first, followed by the Six Nations champions England and then the ever improving Italians.
"It will require a massive effort on our part to overcome such physical size and power but we intend to give it our best shot."
IRELAND UNDER-20 Squad (2012 IRB Junior World Championship, South Africa):
Tadhg Beirne (Lansdowne/Leinster)
Shane Buckley (Garryowen/Munster) *
Jake Cawley (Old Belvedere/Leinster)
Jordon Coghlan (UCD/Leinster)
Sam Coghlan Murray (UCD/Leinster)
Jack Conan (Old Belvedere/Leinster)
Aaron Conneely (Corinthians/Connacht) *
Barry Daly (UCD/Leinster)
Chris Farrell (Dungannon/Ulster)
Tadhg Furlong (Clontarf/Leinster) *
Conor Gilsenan (UCD/Mullingar/Leinster)
JJ Hanrahan (UL Bohemians/Munster) *
Iain Henderson (Queen's University/Ulster) *
Paddy Jackson (Dungannon/Ulster) *
Shane Layden (Buccaneers/Connacht)
Kieran Marmion (Corinthians/Connacht) *
Cathal Marsh (Dublin University/Leinster)
Luke McGrath (UCD/Leinster)
Des Merrey (Clontarf/Leinster)
Peter Nelson (Dungannon/Ulster)
Alan O'Connor (UCD/Leinster)
Stuart Olding (Belfast Harlequins/Ulster)
James Rael (Garryowen/Munster)
Peter Reilly (Lansdowne/Leinster)
Niall Scannell (Dolphin/Munster)
Mikey Sherlock (Clontarf/Leinster)
Josh van der Flier (UCD/Leinster)
* Featured in 2011 Junior World Championship
2012 IRB JUNIOR WORLD CHAMPIONSHIP -
POOL B FIXTURES:
All kick-off times are local -
Monday, June 4: England v Italy, 4.45pm (University of Western Cape Stadium, Cape Town)
Monday, June 4: South Africa v Ireland, 6.45pm (Danie Craven Stadium, Stellenbosch)
Friday, June 8: South Africa v Italy, 6.45pm (University of Western Cape Stadium, Cape Town)
Friday, June 8: England v Ireland, 6.45pm (Danie Craven Stadium, Stellenbosch)
Tuesday, June 12: Ireland v Italy, 2.45pm (Danie Craven Stadium, Stellenbosch)
Tuesday, June 12: South Africa v England, 6.45pm (Danie Craven Stadium, Stellenbosch)