The list of ship decommissionings in 1900 includes a chronological list of ships decommissioned in 1900. 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 1900 instead.
| Date | Operator | Ship | Class and type | Fate and other notes |
|---|---|---|---|---|
| 18 May | Isabel II | Velasco-class unprotected cruiser | hulked; stricken in 1907 or 1935 [1] [2] | |
| Unknown date | Almansa | Floating jetty | Ex-screw frigate; hulked since 1894; decommissioned and sold for scrap in either 1899, [3] 1900, [4] or 1901 [5] (according to different sources) |