The 2011 HP Open was a tennis tournament played on outdoor hard courts. It was the third edition of the HP Open, and part of the WTA International tournaments of the 2011 WTA Tour. It was held at the Utsubo Tennis Center in Osaka, Japan, from October 10 through October 16, 2011. Second-seeded Marion Bartoli won the singles title.
Finals
Singles
Marion Bartoli defeated 
Samantha Stosur, 6–3, 6–1
- It was Bartoli’ 2nd title of the year and the 7th of her career.
Doubles
Kimiko Date-Krumm / 
Zhang Shuai defeated 
Vania King / 
Yaroslava Shvedova, 7–5, 3–6, [11–9]
WTA players
Seeds
| Country | Player | Rank1 | Seed |
|---|---|---|---|
| AUS
|
Samantha Stosur | 7 | 1 |
| FRA
|
Marion Bartoli | 10 | 2 |
 GER
|
Angelique Kerber | 30 | 3 |
 CZE
|
Petra Cetkovská | 32 | 4 |
| AUS
|
Jarmila Gajdošová | 34 | 5 |
| JPN
|
Ayumi Morita | 40 | 6 |
 RSA
|
Chanelle Scheepers | 41 | 7 |
| USA
|
Christina McHale | 49 | 8 |
- Seeds are based on the rankings of October 3, 2011.
Other entrants
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
