| 2005 Croatia Open Umag | |
|---|---|
| Date | 25–31 July |
| Edition | 16th |
| Category | International Series |
| Draw | 32S / 16D |
| Prize money | $375,000 |
| Surface | Clay / outdoor |
| Location | Umag, Croatia |
| Champions | |
| Singles | |
 Guillermo Coria[1] | |
| Doubles | |
 Jiří Novák / Petr Pála[2] | |
The 2005 Croatia Open Umag was a men's tennis tournament played on outdoor clay courts. It was the 16th edition of the Croatia Open Umag, and was part of the International Series of the 2005 ATP Tour. It took place at the International Tennis Center in Umag, Croatia, from 25 July through 31 July 2005. Second-seeded Guillermo Coria won the singles title.
- ^ "2005 Umag – Singles draw". Association of Tennis Professionals (ATP).
- ^ "2005 Umag – Doubles draw". Association of Tennis Professionals (ATP).