| Navy | The Royal Dutch Navy |
| Type | Submarine |
| Class | O 21 |
| Pennant | P 23 |
| Built by | Rotterdamsche Droogdok Maatschappij, (Rotterdam , Holland) |
| Ordered | 21 Jun, 1937 |
| Laid down | 12 Oct, 1937 |
| Launched | 5 Dec, 1939 |
| Commissioned | 13 May, 1940 |
| End service | 1 Dec, 1948 |
| Loss position | |
| History | Decommissioned on 1 December 1948. Sold to be broken up for scrap in April 1949. For the complete service history of this ship see this website (offsite link). Commanding Officers: Lt.Cdr. Gerardus Bernardus Michael van Erkel Lt.Cdr. Albertus Marinus Valkenburg Lt.Cdr. Gerardus Bernardus Michael van Erkel Lt.Cdr. Karel van Dongen Lt.Cdr. Albertus Marinus Valkenburg Lt.Cdr. Arie Jan Schouwenaar |
| Former name | K XXIII |
| Noteable events involving O 23 include: 30 Jun, 1941 16 Aug, 1941 27 Jul, 1942 29 Jul, 1942 2 Aug, 1942 25 Oct, 1942 |

