| Surname | Costello | |||
| First Name(s) | John | |||
| Place of Birth | Blackley | |||
| Club(s) | Glossop Stockport County | |||
| Service | Royal Navy | |||
| Rank | Sergeant | |||
| Service Number | PLY/428(S) | |||
| Previous Service Number(s) | - | |||
| Regiment or Corps | Royal Marine Light Infantry | |||
| Unit(s) | Plymouth Battalion RND | |||
| Previous Regiment(s) or Corps | - | |||
| Unit(s) | - | |||
| Type of Casualty (If applicable) | Died of Wounds | |||
| Theatre of War (If applicable) | Balkan Theatre | |||
| Date of Death (If applicable) | 24/06/1915 | |||
| Place of Death (If applicable) | Gallipoli | |||
| Place of Burial/Commemoration (If applicable) | Plymouth Naval Memorial | |||
| Grave/Memorial Reference (If applicable) | 7. | |||
| Awards and Decorations | - | |||
| Citation(s) | ||||
| Supplementary Notes |
