The 2011 ATP Studena Croatia Open was a men's tennis tournament played on outdoor clay courts. It was the 22nd edition of the ATP Studena Croatia Open, and was part of the ATP World Tour 250 Series of the 2011 ATP World Tour. It took place at the International Tennis Center in Umag, Croatia, from 26 July through 31 July 2011.
| Country | width=150 | Player | Ranking* | Seeding |
|---|---|---|---|---|
 Argentina | Juan Ignacio Chela | 21 | 1 | |
 Ukraine | Alexandr Dolgopolov | 27 | 2 | |
| Ivan Ljubičić | 31 | 3 | ||
| Marin Čilić | 32 | 4 | ||
 Spain | Tommy Robredo | 36 | 5 | |
 Italy | Fabio Fognini | 38 | 6 | |
| Italy | Andreas Seppi | 39 | 7 | |
| Ivan Dodig | 41 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
See main article: 2011 ATP Studena Croatia Open – Singles qualifying.
See main article: 2011 ATP Studena Croatia Open – Singles. Alexandr Dolgopolov defeated Marin Čilić, 6–4, 3–6, 6–3
See main article: 2011 ATP Studena Croatia Open – Doubles. Simone Bolelli / Fabio Fognini defeated Marin Čilić / Lovro Zovko, 6–3, 5–7, [10–7]
