| Ty Derw, Druidstone Road, Old St Mellons, Cardiff CF3 6XD | Detached | 6 | £1,300,000 | 2025-11-21 |
| 186, Mortimer Avenue, Old St Mellons, Cardiff CF3 6YF | Semi_Detached | - | £290,000 | 2025-11-21 |
| Apartment 25, Block 3 The Risings, Ffordd Williamson, Old St Mellons, Cardiff CF3 6AW | Flat | 1 | £157,500 | 2025-10-16 |
| 120, Church Road, Old St Mellons, Cardiff CF3 6YN | Semi_Detached | 3 | £286,000 | 2025-10-14 |
| 245, Church Road, Old St Mellons, Cardiff CF3 6YX | Flat | 2 | £180,000 | 2025-10-03 |
| 14, Potter Street, Old St Mellons, Cardiff CF3 6AR | Terracedd | 3 | £260,000 | 2025-08-21 |
| 1, Clos Thomas, Old St Mellons, Cardiff CF3 6YR | Detached | - | £340,000 | 2025-08-15 |
| 9, Boyce Way, Old St Mellons, Cardiff CF3 6AB | Terracedd | - | £235,000 | 2025-08-15 |
| 26, Stryd Boyd, Old St Mellons, Cardiff CF3 6YS | Terracedd | 2 | £229,000 | 2025-08-01 |
| 106, Heol Bennett, Old St Mellons, Cardiff CF3 6AG | Semi_Detached | 3 | £276,000 | 2025-07-31 |
| Plough House, Druidstone Road, Old St Mellons, Cardiff CF3 6XD | Detached | 3 | £1,055,000 | 2025-07-31 |
| 179, Mortimer Avenue, Old St Mellons, Cardiff CF3 6YG | Semi_Detached | - | £290,000 | 2025-07-24 |
| White Acre, Bridge Road, Old St Mellons, Cardiff CF3 6UY | Detached | 4 | £840,000 | 2025-07-22 |
| 10, Ffordd Crabtree, Old St Mellons, Cardiff CF3 6AN | Terracedd | 2 | £227,500 | 2025-07-18 |
| 42, Rhodfa Leonard, Old St Mellons, Cardiff CF3 6YW | Terracedd | 3 | £260,000 | 2025-06-30 |