List of ship commissionings in 1866
The list of ship commissionings in 1866 is a chronological list of ships commissioned in 1866. In cases where no official commissioning ceremony was held, the date of service entry may be used instead.
| Date | Operator | Ship | Pennant | Class and type | Notes |
| March | ' | – | Screw frigate | ||
| June | ' | – | Armored frigate |