List of ship decommissionings in 1870
The list of ship decommissionings in 1870 includes a chronological list of all ships decommissioned in 1870.
| Date | Operator | Ship | Pennant | Class and type | Fate and other notes |
| 7 January | Contoocook | Contoocook-class sloop | Reused as a quarantine ship until 1872. | ||
| 29 July | Quinnebaug | Decommissioned and laid up in New York before she was broken up in 1871. | |||
| 11 October | Kearsarge | Mohican-class sloop | Decommissioned at the Mare Island Navy Yard before she was recommissioned in 1873. | ||
| 5 December | Piscataqua | Java-class frigate | Decommissioned and laid up in New York, where she sank in 1876 | ||
| December 31 | Laid up at Key West and towed to Philadelphia Navy Yard until recommissioned in 1872. |