The list of ship decommissionings in 2004 includes a chronological list of all ships decommissioned in 2004.
| Operator | Ship | Flag | Class and type | Fate | Other notes | |
|---|---|---|---|---|---|---|
| 17 August |  Royal Navy
|
Sir Percivale | Round Table-class landing ship logistics | Scrapped | ||
| 25 August |  United States Navy
|
Thorn | Spruance-class destroyer | Awaiting disposal in fleet exercises | ||
| 30 August | United States Navy
|
Valley Forge | Ticonderoga-class cruiser | Sunk as a target | ||
| 10 September | United States Navy
|
Portsmouth | Los Angeles-class submarine | Nuclear submarine recycling | ||
| 24 September | United States Navy
|
O'Brien | Spruance-class destroyer | Sunk as a target | ||
| 30 September | United States Navy
|
Ticonderoga | Ticonderoga-class cruiser | Inactive | Ship's Maintenance Facility in Philadelphia, Pennsylvania | |
| 1 October | United States Navy
|
Fletcher | Spruance-class destroyer | Awaiting disposal | ||
| 1 October | United States Navy
|
Sacramento | Sacramento-class fast combat support ship | Undergoing scrapping | ||
| 14 October | United States Navy
|
Parche | Sturgeon-class submarine | Nuclear submarine recycling | ||
| 19 October | Royal Navy
|
Sandown | Sandown-class minehunter | Sold to Estonia | ||
| 25 October | Royal Navy
|
Glasgow | Type 42 destroyer | Scrapped | ||
| 5 November | Royal Navy
|
Newcastle | Type 42 destroyer | Scrapped | ||
| 15 November | Royal Navy
|
Inverness | Sandown-class minehunter | Sold to Estonia | ||
| 3 December | United States Navy
|
Yorktown | Ticonderoga-class cruiser | Awaiting disposal |