It was the first time the O2 arena hosted the ATP World Tour Year-End Singles and Doubles Championships.

Following his Australian Open triumph he reached the final of the ABN AMRO World Tennis Tournament losing to Andy Murray.

[11] He then won three straight titles at the Monte-Carlo Rolex Masters,[12] the Internazionali BNL d'Italia[13] and at the Barcelona Open Banco Sabadell.

He was the four-time defending champion at Roland Garros and had a 31-match winning streak in Paris, broken with a surprise fourth round loss to No.

This is his 3rd appearance On 5 July – after the 2009 Wimbledon Championships – Roger Federer of Switzerland who won his 15th Slam at the tournament over Andy Roddick was announced as the second qualifier.

Roger Federer began the year with a loss to Rafael Nadal at the final of the Australian Open.

He won his first title of the year at the Mutua Madrileña Madrid Open defeating Nadal in the final.

After Nadal's early exit, Federer snapped up the French Open, beating Robin Söderling 6–1, 7–6, 6–4 in the final [19] to complete the career Grand Slam.

[20] He won his 4th title of the year at the Western & Southern Financial Group Masters defeating Novak Djokovic.

On 20 August – After his title in the 2009 Rogers Masters defeating Juan Martín del Potro, Andy Murray of Great Britain was announced as the third qualifier.

[24] As well as at Queens,[25] in the Rogers Cup[26] and in the Open de Tenis Comunidad Valenciana defeating Mikhail Youzhny.

On 10 September – Novak Djokovic of Serbia the defending champion was the Fourth to qualify following his third straight semifinal appearance at the 2009 US Open.

On 15 September – after his first Slam win at the 2009 US Open over Roger Federer, Juan Martín del Potro of Argentina became the fifth qualifier.

At the Slams, he also reached the semifinals of the Australian Open losing to Federer after defeating Novak Djokovic.

On 12 November – After Verdasco fell to Čilić in the third round of the 2009 BNP Paribas Masters last years runner-up Nikolay Davydenko of Russia took one of the last two remaining spots.

[43] The following week he won the ATP Studena Croatia Open Umag defeating Juan Carlos Ferrero.

On 13 November after both Söderling and Tsonga fell to Djokovic and Nadal respectively in the quarterfinals of the 2009 BNP Paribas Masters Australian Open semifinalist Fernando Verdasco occupied the last remaining spot.

Fernando Verdasco started the year well with a semifinal appearance Australian Open losing to Rafael Nadal in a tournament record 5 hour 14 minute battle after five sets.

After Roddick's withdrawal due to left leg injury on 17 November Robin Söderling was announced as his replacement.

They started with back-to-back runner-up finishes at the Qatar ExxonMobil Open and at the Medibank International Sydney to the Bryans.

[58] They then claimed three back-to-back titles at Monte-Carlo[59] and Internazionali BNL d'Italia[60] and the Barcelona Open Banco Sabadell.

[62] The Canadian-Serbian duo hit back from a two-set deficit in The Championships semi-finals at Wimbledon, against James Blake and Mardy Fish, before edging the Bryans in a four-set final.

[63] They won their 7th and 8th titles at the Western & Southern Financial Group Masters[64] and at the Davidoff Swiss Indoors.

[72] They also reached 5 other finals, Monte-Carlo, Internazionali BNL d'Italia, Wimbledon, Western & Southern Financial Group and Davidoff.

Knowles won the Regions Morgan Keegan Championships with Fish[75] and the Wimbledon mixed doubles with Anna-Lena Grönefeld.

They won one of these finals at the Sony Ericsson[85] and lost the BNP Paribas Open and the Rogers Masters.

Ram separately finished as runner-up at the Australian mixed doubles with Nathalie Dechy and at the Open 13 with Julian Knowle.

Group A: Consisted of Roger Federer, Andy Murray, Juan Martín del Potro and Fernando Verdasco.

Against the rest of the group, Roger Federer was 12–7, Andy Murray was 17–5, Juan Martín del Potro was 2–10 and Fernando Verdasco was 1–10.

Murray played Verdasco, hoping for a straight set shot through to the semi-final, leaving Federer and Del Potro to fight for the other spot.