| Ahn Sun-ju | |
| Fullname: | Sun-ju Ahn |
| Nickname: | Big Mama |
| Birth Date: | 31 August 1987 |
| Birth Place: | Gwangju, Gyeonggi-do, South Korea |
| Spouse: | Kim Sung-ho |
| Yearpro: | 2006 |
| Tour: | LPGA of Japan Tour (joined 2010) |
| Extour: | LPGA of Korea Tour (joined 2006) |
| Prowins: | 35 |
| Lpgawins: | 1 |
| Jlpgawins: | 28 |
| Klpgawins: | 7 |
| Nabisco: | CUT: 2008 |
| Lpga: | DNP |
| Wusopen: | T13: 2009 |
| Wbritopen: | T9: 2014 |
| Evian: | DNP |
| Award1: | LPGA of Japan Tour Player of the Year |
| Year1: | 2010, 2011, 2014 |
| Award2: | LPGA of Japan Tour leading money winner |
| Year2: | 2010, 2011, 2014, 2018 |
| Award3: | LPGA of Japan Tour Rookie of the Year |
| Year3: | 2010 |
| Hangul: | 안선주 |
| Hanja: | 安宣柱 |
| Rr: | An Seonju |
| Mr: | An Sŏnju |
Ahn Sun-ju, or Sun-ju Ahn (ko|안선주, born 31 August 1987) is a South Korean professional golfer currently playing on the LPGA of Japan Tour. She led the LPGA of Japan Tour money list in 2010, 2011, 2014, and 2018.
LPGA Tour playoff record (1–0)
| No. | Date | Tournament | Winning score | Margin of victory | Runner(s)-up | |
|---|---|---|---|---|---|---|
| 1 | 13 May 2006 | KB Star Tour First Tourney in Yongin | −16 (65-66-69=200) | 1 stroke |  Na Yeon Choi | |
| 2 | 21 Apr 2007 | KB Star Tour First Tourney in Busan | +4 (68-76-76=220) | 1 stroke | ||
| 3 | 20 May 2007 | Taeyoung Cup Korea Women's Open | −4 (73-69-70=212) | 4 strokes | ||
| 4 | 6 Jul 2007 | MBC Tour Korea Golf Art Village Open | −12 (69-63=132) | 1 stroke | Eun-Hee Ji | |
| 5 | 3 Oct 2008 | Samsung Finance Ladies Championship | −10 (65-69-72=206) | 2 strokes | Yoon Chae-young | |
| 6 | 10 May 2009 | KB Star Tour First Tourney in Hampyeong | −12 (68-66-70=204) | 6 strokes | Hee Kyung Seo | |
| 7 | 6 Sep 2009 | KB Star Tour Second Tourney in Kyeongsan | −17 (68-66-66=202) | 3 strokes | Song Min-ji |
| No. | Date | Tournament | Winning score | Margin of victory | Runner(s)-up | |
|---|---|---|---|---|---|---|
| 1 | 8 Mar 2010 | Daikin Orchid Ladies | −10 (69-70-67=206) | 5 strokes |  Kaori Aoyama Chie Arimura Shinobu Moromizato Inbee Park Jiyai Shin | |
| 2 | 18 Jul 2010 | Stanley Ladies | −6 (70-71-69=210) | Playoff | Lee Ji-hee | |
| 3 | 10 Oct 2010 | Sankyo Ladies Open | −10 (69-70-67=206) | Playoff | Inbee Park | |
| 4 | 17 Oct 2010 | Fujitsu Ladies | −19 (65-62-70=207) | 7 strokes | Jiyai Shin | |
| 5 | 8 May 2011 | World Ladies Championship Salonpas Cup | −10 (71-67-71-69=278) | 3 strokes | ||
| 6 | 12 Jun 2011 | Suntory Ladies Open | −14 (67-70-67-70=274) | 1 stroke | ||
| 7 | 14 Aug 2011 | NEC Karuizawa 72 | −16 (68-66-66=200) | Playoff | Akiko Fukushima | |
| 8 | 9 Oct 2011 | Sankyo Ladies Open | −9 (71-66-70=207) | 2 strokes | Lee Ji-woo Jeon Mi-jeong Shiho Oyama | |
| 9 | 6 May 2012 | World Ladies Championship Salonpas Cup | −8 (67-69-72=208) | Playoff | Inbee Park  Morgan Pressel | |
| 10 | 26 Aug 2012 | Nitori Ladies | −14 (71-63-68=202) | 2 strokes | Jeon Mi-jeong | |
| 11 | 2 Sep 2012 | Golf5 Ladies | −15 (67-68-66=201) | 1 stroke | Lee Ji-hee | |
| 12 | 25 Aug 2013 | CAT Ladies | −12 (70-68-60=198) | 3 strokes | Ritsuko Ryu | |
| 13 | 1 Sep 2013 | Nitori Ladies Golf Tournament | −11 (70-70-65=205) | 2 strokes |  Teresa Lu | |
| 14 | 6 April 2014 | Yamaha Ladies Open Katsuragi | −5 (70-69-72-72=283) | 1 stroke | Yumiko Yoshida | |
| 15 | 25 May 2014 | Chukyo TV Bridgestone Ladies Open | −8 (69-69-70=208) | 3 strokes | Lee Ji-hee Sakai Miki Ritsuko Ryu Miki Saiki Phoebe Yao Sakura Yokomine | |
| 16 | 15 Jun 2014 | Suntory Ladies Open | −14 (69-71-68-66=274) | 5 strokes | Akane Iijima | |
| 17 | 12 Oct 2014 | Stanley Ladies Golf Tournament | −14 (68-68-66=202) | 2 strokes | Lee Ji-hee | |
| 18 | 19 Oct 2014 | Fujitsu Ladies | −11 (64-69-72=205) | Playoff | Sakura Yokomine Erika Kikuchi | |
| 19 | 26 Jul 2015 | Century 21 Ladies Golf Tournament | −15 (64-67-70=201) | 1 stroke | Erika Kikuchi Bae Hee-kyung | |
| 20 | 8 Nov 2015 | Toto Japan Classic^ | −16 (68-65-67=200) | Playoff | Lee Ji-hee Angela Stanford | |
| 21 | 24 Jul 2016 | Century 21 Ladies Golf Tournament | −9 (73-67-67=207) | 1 stroke | Megumi Kido Erika Kikuchi | |
| 22 | 9 Oct 2016 | Stanley Ladies | −6 (69-69=138) | Playoff | Lee Bo-mee | |
| 23 | 5 Mar 2017 | Daikin Orchid Ladies Golf Tournament | −6 (73-67-69-73=282) | 1 stroke | Fumika Kawagishi | |
| 24 | 11 Mar 2018 | Yokohama Tire Golf Tournament PRGR Ladies Cup | −11 (71-66-68=205) | Playoff | Ai Suzuki | |
| 25 | 1 Apr 2018 | Yamaha Ladies Open Katsuragi | −5 (72-71-71-69=283) | 2 strokes | Erika Kikuchi | |
| 26 | 8 Jul 2018 | Nipponham Ladies Classic | −13 (69-67-67=203) | 2 strokes | Fumika Kawagishi | |
| 27 | 26 Aug 2018 | Nitori Ladies Golf Tournament | −7 (70-70-71-70=281) | 3 strokes | Ayaka Watanabe | |
| 28 | 21 Oct 2018 | Nobuta Group Masters GC Ladies | −12 (65-70-67-74=276) | 2 strokes | Kim Ha-neul |