| MD | Players | Nationality | DOB | A(D) |
|---|---|---|---|---|
| 14-Jan-2018 | Jordan Larmour | Ireland | 10-Jun-1997 | 20(218) |
| 14-Oct-2017 | James Ryan | Ireland | 24-Jul-1996 | 21(82) |
| 14-Oct-2017 | Joey Carbery | Ireland | 01-Nov-1995 | 21(348) |
| 14-Oct-2017 | Ross Byrne | Ireland | 08-Apr-1995 | 22(190) |
| 10-Dec-2017 | Gary Ringrose | Ireland | 26-Jan-1995 | 22(319) |
| 14-Oct-2017 | Adam Byrne | Ireland | 10-Apr-1994 | 23(187) |
| 20-Jan-2018 | Dan Leavy | Ireland | 23-May-1994 | 23(242) |
| 14-Oct-2017 | Robbie Henshaw | Ireland | 12-Jun-1993 | 24(124) |
| 14-Oct-2017 | Josh van der Flier | Ireland | 25-Apr-1993 | 24(172) |
| 14-Oct-2017 | Luke McGrath | Ireland | 03-Feb-1993 | 24(253) |
| 14-Oct-2017 | Tadhg Furlong | Ireland | 14-Nov-1992 | 24(334) |
| 14-Oct-2017 | Barry Daly | Ireland | 19-Sep-1992 | 25(25) |
| 14-Oct-2017 | Jack Conan | Ireland | 29-Jul-1992 | 25(77) |
| 14-Jan-2018 | James Lowe | Wales | 08-Jul-1992 | 25(190) |
| 20-Jan-2018 | Jamieson Gibson-Park | Ireland | 10-May-1992 | 25(255) |
| 14-Oct-2017 | James Tracy | Ireland | 02-Apr-1991 | 26(196) |
| 14-Jan-2018 | Jordi Murphy | Ireland | 22-Apr-1991 | 26(268) |
| 14-Oct-2017 | Rhys Ruddock | Ireland | 13-Oct-1990 | 27(1) |
| 21-Oct-2017 | Noel Reid | Ireland | 22-May-1990 | 27(152) |
| 14-Oct-2017 | Jack McGrath | Ireland | 11-Oct-1989 | 28(3) |
| 21-Oct-2017 | Cian Healy | Ireland | 07-Oct-1987 | 30(15) |
| 10-Dec-2017 | Sean O'Brien | Ireland | 14-Feb-1987 | 30(300) |
| 14-Oct-2017 | Devin Toner | Ireland | 29-Jun-1986 | 31(107) |
| 21-Oct-2017 | Fergus McFaddon | Ireland | 17-Jun-1986 | 31(126) |
| 21-Oct-2017 | Sean Cronin | Ireland | 06-May-1986 | 31(168) |
| 21-Oct-2017 | Jonathan Sexton | Ireland | 11-Jul-1985 | 32(102) |
| 21-Oct-2017 | Scott Fardy | Australia | 05-Jul-1984 | 33(108) |
| 10-Dec-2017 | Robert Kearney | Ireland | 26-Mar-1983 | 34(260) |
| 14-Oct-2017 | Isikeli Nacewa | Fiji | 22-Jul-1982 | 35(85) |
MD = Match date,
DOB = Date of birth,
A(D) = Age(days).