| Diogo de Melo de Castro | |
| Order: | 11th & 13th |
| Office: | Governor of Portuguese Ceylon |
| Term Start: | 1633 |
| Term End: | 1635 |
| Predecessor: | Jorge de Almeida |
| Successor: | Jorge de Almeida |
| Term Start2: | 1636 |
| Term End2: | 1638 |
| Monarch2: | Philip III of Portugal |
| Predecessor2: | Jorge de Almeida |
| Successor2: | António Mascarenhas |
Diogo de Melo de Castro was the 11th & 13th Governor of Portuguese Ceylon. De Melo was first appointed in 1633 under Philip III of Portugal, he was Governor until 1635 and then in 1636 until 1638. He died in the Battle of Gannoruwa and was succeeded by Jorge de Almeida and António Mascarenhas respectively.[1]