St. Mirren B: every transfer in and out, fees paid and earned, squad market value.
| Date | Player | From | To | Fee |
|---|---|---|---|---|
| 2025-07-15 | Billy Hutchinson | St. Mirren B | Clydebank FC | Free |
| 2025-07-01 | Billy Hutchinson | St. Mirren U18 | St. Mirren B | — |
| 2024-01-18 | Gallagher Lennon | St. Mirren B | Dumbarton | Loan |
| 2023-12-02 | Gallagher Lennon | St. Mirren B | Linlithgow Rose | Loan |
| 2023-07-01 | Luke Kenny | St. Mirren B | St. Mirren | — |
| 2023-07-01 | Gallagher Lennon | Partick Th. U18 | St. Mirren B | Free |
| 2023-07-01 | Fraser Taylor | St. Mirren B | St. Mirren | — |
| 2023-07-01 | Andrew Gaffney | St. Mirren B | St. Mirren | — |
| 2022-12-01 | Luke Kenny | St. Mirren B | East Kilbride | Loan |
| 2022-07-01 | Andrew Gaffney | St. Mirren U18 | St. Mirren B | — |
| 2021-12-28 | Luke Kenny | St. Mirren B | East Kilbride | Loan |
| 2021-12-28 | Fraser Taylor | St. Mirren B | Cumbernauld CFC | Loan |
| 2021-11-01 | Fraser Taylor | St. Mirren B | Cumbernauld CFC | Loan |
| 2021-07-17 | Luke Kenny | St. Mirren B | East Kilbride | Loan |
| 2021-07-01 | Luke Kenny | St. Mirren U18 | St. Mirren B | — |
| 2021-07-01 | Fraser Taylor | St. Mirren U18 | St. Mirren B | — |
| 2020-07-01 | Jay Henderson | St. Mirren B | St. Mirren | — |
| 2019-07-01 | Jay Henderson | St. Mirren U18 | St. Mirren B | — |