Tadhg Beirne makes his first start of the campaign, partnering Iain Henderson in the second row, with a new-look back row seeing Jordan Coghlan link up with Conor Gilsenan and Jack Conan.
Changes to the backs see Foster Horan, the try scorer against France, named on the left wing and Kieran Marmion returning to the scrum half position.
Speaking ahead of Friday's game against the Italians, Ruddock said: "We are looking forward to this week's test and in particular looking forward to backing up our two previous displays.
"We achieved victory in our last two games because we have outworked the opposition and expect the same this week along with a quality display of skills."
The Ireland Under-20s' clash with Italy will be broadcast live online from Dubarry Park on the RTÉ website (Island of Ireland only).
IRELAND UNDER-20 Team & Replacements (v Italy Under-20s, RBS Under-20 6 Nations Championship, Dubarry Park, Athlone, Friday, February 24, kick-off 7.05pm):
15 - Shane Layden (Buccaneers/Connacht)
14 - Conor Finn (Buccaneers/Connacht)
13 - Chris Farrell (Dungannon/Ulster)
12 - JJ Hanrahan (UL Bohemians/Munster)
11 - Foster Horan (Lansdowne/Leinster)
10 - Paddy Jackson (Dungannon/Ulster) (capt)
9 - Kieran Marmion (Corinthians/Connacht)
1 - Kyle McCall (Ballynahinch/Ulster)
2 - Niall Scannell (Dolphin/Munster)
3 - Peter Reilly (Lansdowne/Leinster)
4 - Tadhg Beirne (Lansdowne/Leinster)
5 - Iain Henderson (Queen's University/Ulster)
6 - Jordan Coghlan (UCD/Leinster)
7 - Conor Gilsenan (UCD/Leinster)
8 - Jack Conan (Old Belvedere/Leinster)
16 - James Rael (Garryowen/Munster)
17 - Des Merrey (Clontarf/Leinster)
18 - Jake Cawley (Old Belvedere/Leinster)
19 - Daniel Qualter (Buccaneers/Connacht)
20 - Aaron Conneely (Corinthians/Connacht)
21 - Luke McGrath (UCD/Leinster)
22 - Cathal Marsh (Dublin University/Leinster)
23 - Stuart Olding (Belfast Harlequins/Ulster)
Ireland Under-20s' 2012 Fixtures/Results:
Friday, February 3 - Ireland U-20s 11 Wales U-20s 6, Dubarry Park, Buccaneers RFC
Saturday, February 11 - France U-20s 12 Ireland U-20s 13, Stade des Alpes, Grenoble
Friday, February 24 - Ireland U-20s v Italy U-20s, Dubarry Park, Buccaneers RFC, 7.05pm
Friday, March 9 - Ireland U-20s v Scotland U-20s, Dubarry Park, Buccaneers RFC, 7.05pm
Friday, March 16 - England U-20s v Ireland U-20s, Adams Park, London Wasps RFC, 8.05pm