See main article: 2011 Serbia Open.
Novak Djokovic defeated Feliciano López in the final, 7–6(7–4), 6–2 to win the singles tennis title at the 2011 Serbia Open. It was his 27th consecutive win of the season.
Sam Querrey was the reigning champion, but chose not to participate this year.
The first four seeds received a bye in to the Second Round.
See main article: 2011 Serbia Open – Singles qualifying.