The 2011 Winston-Salem Open was a men's tennis tournament played on outdoor hard courts. It was previously known as the Pilot Pen Tennis but was relocated to Winston-Salem. It was the 43rd edition of the Winston-Salem Open, and was part of the ATP World Tour 250 series of the 2011 ATP World Tour. It took place at the Wake Forest University in Winston-Salem, North Carolina, United States, from August 22 through August 27, 2011. It was the last event on the 2011 US Open Series before the 2011 US Open.
Fourth-seeded John Isner won the singles title.
| Country | width=150 | Player | Ranking* | Seed |
|---|---|---|---|---|
| 15 | 1 | |||
 Austria | 18 | 2 | ||
 Ukraine | 22 | 3 | ||
| 27 | 4 | |||
 Russian Federation | 31 | 5 | ||
| Kevin Anderson | 35 | 6 | ||
 Argentina | 39 | 7 | ||
 Cyprus | 40 | 8 | ||
| Ukraine | 42 | 9 | ||
| 43 | 10 | |||
| Russian Federation | 44 | 11 | ||
 Spain | 46 | 12 | ||
 Finland | 51 | 13 | ||
| 56 | 14 | |||
 Colombia | 57 | 15 | ||
| Russian Federation | 59 | 16 |
The following players received wildcards into the singles main draw
The following players received entry from the qualifying draw:
See main article: 2011 Winston-Salem Open – Singles qualifying.
The following players received entry from a lucky loser spot:
See main article: 2011 Winston-Salem Open – Singles. 
John Isner defeated 
Julien Benneteau, 4–6, 6–3, 6–4
See main article: 2011 Winston-Salem Open – Doubles. 
Jonathan Erlich / Andy Ram defeated Christopher Kas / Alexander Peya, 7–6(7–2), 6–4
