The list of ship decommissionings in 1939 is a chronological list of all ships decommissioned in 1939. In cases where no official decommissioning ceremony was held, the date of withdrawal from service may be used instead. For ships lost at sea, see list of shipwrecks in 1939 instead.
| Operator | Ship | Class and type | Fate | Other notes | |
|---|---|---|---|---|---|
| 2 October |  Southern Railway Co | Dinard | ferry | Converted into a hospital ship [1] | Renamed HM Hospital Ship No 28 |