Additions
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 11/2021 |  | Pat Devlin | MA |  | Cabinteely FC | Cabinteely FC |
| 09/2021 | | Ryan Bowden | DF | |||
| 09/2021 | | Cian Connors | GK | |||
| 09/2021 | | Jamie Callaghan | MF |  | Bray Wanderers U19 | U19 |
| 09/2021 | | Sam Hayden | MF | |||
| 07/2021 | | Callum Thompson | FW |  | Longford Town | Longford Town |
| 07/2021 | | Sam Verdon | FW | | Longford Town | Longford Town |
| 07/2021 |  | Daniel Jones | DF |  | Hereford FC | Hereford FC |
| 04/2021 | | Jack Hughes | MF | |||
| 03/2021 | | Charlie Gallagher | MF | |||
| 03/2021 | | Toby Owens | MF | |||
| 02/2021 | | Andrew Quinn | DF | |||
| 02/2021 | | Mark Byrne | MF | |||
| 02/2021 | | Darren Craven | MF | |||
| 01/2021 | | Brandon Kavanagh | MF |  | Shamrock Rovers | Shamrock |
| 01/2021 | | Kian Clarke | GK | | Shamrock Rovers | Shamrock |
| 01/2021 | | Jack Ross | GK |  | Bray Wanderers U17 | U17 |
| 01/2021 | | Sean Callan | DF | | Shamrock Rovers | Shamrock |
| 01/2021 | | Connor Clifford | MF |  | Derry City | Derry City |
| 01/2021 | | Stephen Kinsella | MF | |||
| 01/2021 | | Ross O'Brien | MF | |||
| 01/2021 | | Richie O'Farrell | MF |  | Drogheda United | Drogheda |
| 01/2021 | | Jamie Bowden | FW |
Departures
| from | Name | Pos | Team | Team | ||
|---|---|---|---|---|---|---|
| 11/2021 | | Callum Thompson | FW | | Longford Town | Longford Town |
| 08/2021 | | Dean O'Shea | DF |  | Galway United | Galway |
| 08/2021 | | Don Franklin | FW |  | Chippenham Town | Chippenham |
| 08/2021 | | Cian Maher | DF |  | Bangor Celtic | Bangor Celtic |
| 07/2021 | | Glen Hollywood | MF |  | St. Patrick's CYFC | St. Patrick's CYFC |
| 03/2021 | | Adam Hayden | GK | | Cabinteely FC | Cabinteely FC |
| 02/2021 |  | Tristan Noack-Hofmann | DF |  | Athlone Town | Athlone Town |
| 01/2021 | | Enda Minogue | GK |  | Bohemian FC | Bohemians |
| 01/2021 | | Kilian Cantwell | DF | | Athlone Town | Athlone Town |
| 01/2021 | | Derek Daly | DF | | Athlone Town | Athlone Town |
| 01/2021 | | John Wilson | DF |  | Shelbourne FC | Shelbourne FC |
| 01/2021 | | Jack Watson | MF | | Athlone Town | Athlone Town |
| 01/2021 |  | Marlon Marishta | FW | | Bohemian FC | Bohemians |