The 2009 WTA Tour Championships (also known as Sony Ericsson Championships – Doha 2009) was held in Doha, Qatar from October 27 to November 1. It was the second time the Khalifa International Tennis Complex hosted the WTA Tour Year-End Singles and Doubles Championships.

Women's Tennis Association (WTA) rank No. 2 Serena Williams won her second year-end championships title, defeating sister, Venus Williams in the final 6–2, 7–6(7–4). The Spanish duo of Nuria Llagostera Vives and María José Martínez Sánchez won the doubles event on their debut 7–6(7–0), 5–7, [10–7]. They defeated the world No. 1s in doubles and defending champions, Cara Black and Liezel Huber, in the final.

Finals

Singles

Serena Williams defeated Venus Williams, 6–2, 7–6(7–4).

Doubles

Nuria Llagostera Vives / María José Martínez Sánchez defeated Cara Black / Liezel Huber, 7–6(7–0), 5–7, [10–7].

Qualifying

Singles

Race Rankings singles (26 October 2009) Rk Name Points Tour Date Qualified 1 Dinara Safina 7731 18 August 5 2 Serena Williams 7576 17 August 19 3 Svetlana Kuznetsova 5772 18 October 5 4 Caroline Wozniacki 5475 24 September 14 5 Elena Dementieva 5415 19 September 14 6 Victoria Azarenka 4451 16 October 9 7 Venus Williams 4397 16 October 9 8 Jelena Janković 3555 18 October 22

On August 5, the first qualifier for the year-end championship was announced in Dinara Safina.

Dinara Safina enjoyed a good start to the year reaching the finals of ASB Classic losing to Elena Dementieva 6–3 2–6 6–1, followed by her second Grand Slam final, her first on a hardcourt in the Australian Open but was thrashed by Serena Williams 6–0 6–3. Safina then became the world no. 1 after Serena's Charleston points dropped off. She then made her 3rd final in the Porsche Tennis Grand Prix but once again ended up on the losing side to Svetlana Kuznetsova 6–4 6–3. She then claimed two titles back-to-back in the Internazionali BNL d'Italia defeating Kuznetsova winning 6–3 6–2; and in the Mutua Madrileña Madrid Open defeating Caroline Wozniacki 6–2 6–4.

She then competed in her 4th straight finals and her 6th of the year at the French Open but once again lost to Kuznetsova 6–4 6–2. She then reached the Semifinals of the Wimbledon Championships but was once again questioned for her credibility as the world no. 1 as Venus Williams crushed her in the most dominating scoreline that a current world no. 1 has ever lost 6–1 6–0. - However she bounce back from that loss by winning the Slovenia Open defeating Sara Errani 6–7(5) 6–1 7–5 in the final. She reached her 8th final in Cincinnati but lost to Jelena Janković 6–4 6–2. Safina struggled in the US Open being pushed in the first and second rounds by much lower ranked players. She ended up losing to Petra Kvitová in the third round 6–4 2–6 7–6(5).

This is Safina's 2nd appearance and is trying to win her first match as she went 0-3 last year.

On August 19 - The second qualifier was announced as Serena Williams following her semifinal appearance at the Rogers Cup.

Serena Williams Began the year by winning the Australian Open. She then reached the final of the Sony Ericsson Open after defeating Venus in the semifinals to keep her no.1 ranking. Playing injured she lost to Victoria Azarenka 6–3, 6–1. From there she went on a four match losing streak, the longest of her career and lost World No. 1 ranking to Safina on April 20 to Dinara Safina when she pulled out of Family Circle Cup. Despite a lack of preparation, Williams reached the quarterfinals of the French Open before losing to the eventual champion Kuznetsova 7–6(4), 5–7, 7–5, which ended her 18–match Grand Slam winning streak.

However she rebounded at Wimbledon defeating Elena Dementieva 6–7(4) 7–5 8–6. The match was named by many as the best match of the year, she then claimed her third title by defeating Venus 7–6(3) 6–2. In the US Open, she reached the semifinals. She reclaimed the no. 1 spot for two weeks from Safina after outperforming Safina in the China Open. This is Serena's sixth appearance and is trying to reclaim the world no. 1 from Dinara Safina. Serena won the event in 2001 and was the runner-up in 2002 and 2004. Serena has a 10–5 record in the year-end championships.

On the 4th of September, Caroline Wozniacki and Elena Dementieva were the third and fourth to qualify, respectively

Elena Dementieva has enjoyed a remarkable season that was begun by winning 15 consecutive matches including titles in ASB Classic and Medibank International Sydney where she defeated the top two seeds Serena Williams and Dinara Safina, she then reached the semifinals of the Australian Open losing to eventual champion Serena 6–3 6–4. She then reached the finals of Open GDF Suez losing to Amélie Mauresmo 7–6(7) 2–6 6–4. At the French Open she was upset by Samantha Stosur after winning her match against Jelena Dokić due to Dokić's retirement. Dementieva played one of the most memorable matches on the Sony Ericsson WTA Tour in 2009 when she was defeated by Serena Williams in the semifinals of Wimbledon (6–7(4) 7–5 8–6) in a marathon that lasted nearly three hours. Dementieva's successful hard court season was highlighted by winning the Rogers Cup in Toronto defeating Maria Sharapova 6–4 6–3 in the finals and clinching the title of US Open Series winner. However she was upset by Melanie Oudin in the second round of the US Open. Dementieva also claimed her career high this year of no. 3 for 7 weeks. This is Dementieva's 9th appearance with her best showing coming from 2000 and 2008 reaching the semifinals. She has 5–16 record in the championship coming to this year's event.

Caroline Wozniacki season was highlighted by 3 titles on 3 different surfaces in MPS Group Championships a green clay event defeating Aleksandra Wozniak 6–1 6–2, In Aegon International a grass event defeating Virginie Razzano 7–6(5) 7–5 and in Pilot Pen Tennis a hardcourt event defeating Elena Vesnina 6–2 6–4. Wozniacki also reached 5 other finals in the Cellular South Cup losing to Azarenka 6–1 6–3, the Family Circle Cup losing to Sabine Lisicki 6–2 6–4, the Mutua Madrileña Madrid Open losing to Safina 6–2 6–4, the Swedish Open losing to María José Martínez Sánchez 7–5 6–4 and her biggest achievement so reaching the finals of the US Open her first time to reach a spot greater than the fourth round, losing to Kim Clijsters 7–5, 6–3 and reaching world no. 5. She will be competing in her 1st year-end championship. She will be making her debut at the year-end championship.

On October 5, Svetlana Kuznetsova became the fifth qualifier.

Svetlana Kuznetsova began the year with a Quarterfinal appearance at the Australian Open where she lost to eventual champion Serena Williams 5–7 7–5 6–1 throwing of a lead in the second set. In the Porsche Tennis Grand Prix Kuznetsova won her first title in two years defeating Safina 6–4 6–3, the following week she once again faced Safina in the final of Internazionali BNL d'Italia however this time she lost 6–3 6–2. At the French Open Kuznetsova made easy work on Safina in the final 6–4 6–2 in just 74 minutes despite struggling against Serena and Samantha Stosur the previous rounds. The 2009 French Open is her 2nd Major, her first being the 2004 US Open. She then had a patch of bad run then on including a third round lost at Wimbledon losing to Lisicki 6–2 7–5 and 4th round lost to Caroline Wozniacki 2–6 7–6(5) 7–6(3) at the US Open. She then won the 2009 China Open over Agnieszka Radwańska 6–2 6–4 this helped her regain the no. 3 ranking. This is Kuznetsova's 5th appearance and trying to rub off an 8 match losing streak at the championship. Kuznetsova has a 1–10 record in the tournament's history.

On October 9 Venus Williams and Victoria Azarenka qualified together as sixth and seventh qualifiers.

Venus Williams is the defending champion. Venus won back-to-back titles in the Dubai Tennis Championships defeating Virginie Razzano 6–4 6–2. En route, she defeated Dementieva and Serena and a title in the Abierto Mexicano Telcel defeating Flavia Pennetta 6–1 6–2 and her first clay title since May 2005. She then went to Wimbledon as the defending champion, losing in the finals to her sister Serena 7–6(3), 6–2 after crushing world no. 1 Dinara Safina 6–1 6–0 the biggest win against a reigning world no. 1. She also reached the final in Stanford losing to Marion Bartoli. In the Grand Slams Venus' performance was not good losing in the 2nd round of Australian Open, 3rd round of the French Open and 4th round of US Open. This is Venus' 4th appearance and she has never lost before the semifinals. Venus has an impressive record of 9–2 in the event.

This is Venus' 4th appearance and she has never lost before the semifinals. Venus has an impressive record of 9–2 in the event, and is the defending champion

Victoria Azarenka is enjoying her best season so far by reaching a career high no. 6. She began the year with her first career title in Brisbane International defeating Marion Bartoli 6–3 6–1, then followed it up with titles in Cellular South Cup defeating Wozniacki 6–1 6–3 and Sony Ericsson Open, defeating five-time Miami champion Serena Williams. She also managed to reach the quarterfinals of the French Open losing to Safina 1–6 6–4 6–2 and Wimbledon losing to eventual champion Serena 6–2 6–3. She will be competing in her 1st year-end championship.

On October 22 Jelena Janković claimed the last spot as Radwańska and Zvonareva fell early at the Kremlin Cup.

Jelena Janković who is having a not so satisfying year, still managed to win the red clay tournament in Andalucia Tennis Experience defeating Carla Suárez Navarro 6–3 3–6 6–3 and Western & Southern Financial Group Women's Open defeating Safina 6–4 6–2. She also became the runner up at Tokyo, retiring in the final against Maria Sharapova due to wrist injury. In Grand Slams Janković the furthest she has reached in a slam was a fourth round. Janković failed to make it past the fourth round of a Grand Slam in 2009. This Janković's 3rd appearance having her best result last year finishing in the semifinals with a 2–5 record coming to the event.

The two alternate spots were taken by Vera Zvonareva, who had a fascinating first half of the year by reaching the semifinal of Australian Open losing to Safina 6–3 7–6(4) and winning two titles in Pattaya Women's Open defeating Sania Mirza 7–5 6–1, an international tournament, and Indian Wells defeating Ana Ivanovic 7–6(5) 6–2 also defeating Wozniacki 6–4 6–2 and Azarenka 6–3 6–3 en route, a Premier Mandatory tournament. She withdrew from Internazionali BNL d'Italia, Mutua Madrileña Madrid Open and Roland Garros with a right ankle injury. In the US Open she lost to Flavia Pennetta in the Fourth Round when she lost 6–0 in the third when she started whipping on court. This will be her 3rd appearance if one of the players withdraw, she has a 4–4 record at the event. The other alternate is Agnieszka Radwańska, who had consistent results throughout the year, reaching at least the quarterfinals in twelve tournaments, including a runner-up finish at the China Open losing to Svetlana Kuznetsova 6–2 6–4, She scored 2 top 10 wins in the year over Ana Ivanovic and Elena Dementieva. This will be Radwańska's second appearance if a second player withdraws she has a 1–0 record at the event

Doubles Race Rankings doubles (26 October 2009) Rk Name Points Tour Date Qualified 1 Cara Black Liezel Huber 9100 20 September 9 2 Venus Williams Serena Williams 6750 5 September 29 3 Nuria Llagostera Vives 6396 19 October 5 4 Rennae Stubbs Samantha Stosur 5048 15 October 12

On September 9 - Cara Black and Liezel Huber, the defending champions, were the first to qualify for the championships after their runner-up finish at Wimbledon.