The list of ship commissionings in 1870 is a chronological list of ships commissioned in 1870. In cases where no official commissioning ceremony was held, the date of service entry may be used instead.
| Operator | Ship | Class and type | Pennant | Other notes | |
|---|---|---|---|---|---|
| 4 March | USS Congress | Sloop | |||
| 13 March | HMVS Cerberus | Cerberus-class breastwork monitor | |||
| April | HMS Captain | Turret ship | [1] | ||
| 28 September | HMS Vanguard | Audacious-class battleship | |||
| 1 October | HMS Invincible | Audacious-class battleship |