Andy Roddick finished the year ranked world No. 1 for the first time in his career. He won six tournaments during the season, including a major title at the US Open. He also won two Masters Series events.
The 2003 ATP Tour was the global elite men's professional tennis circuit organised by the Association of Tennis Professionals (ATP) for the 2003 tennis season. The ATP Tour is the elite tour for professional tennis organised by the ATP. The ATP Tour includes the four Grand Slam tournaments, the Tennis Masters Cup, the ATP Masters Series, the International Series Gold and the International Series tournaments.
The 2003 ATP Tour season saw 3 new Grand Slam champions and saw Andre Agassi win his eighth and last Grand Slam title when winning the Australian Open for the fourth time.[1]Roger Federer would win his first of 20 Grand Slam titles by defeating Aussie Mark Philippoussis 7–6(7–5), 6–2, 7–6(7–3) in the final at Wimbledon.[2] Federer would also win his maiden Tennis Masters Cup by defeating Agassi in the final 6–3, 6–0, 6–4. Federer would win 7 titles overall, including winning in Dubai and Halle, tournaments he would have a lot of success at in later seasons. 2003 would be a breakout season for Federer as a dominant player at the very top of the game, improving his year-end ATP ranking from 6 the previous season to 2.
Andy Roddick also had a breakthrough season by winning his first and only Grand Slam title at the US Open and ending the season as world No. 1, 160 points ahead of Federer. Roddick started the season off with an epic victory in the quarterfinals of the Australian Open over Younes El Aynaoui, winning 21–19 in the fifth set after playing for 4 hours and 59 minutes.[3] By doing this, Roddick reached his first major semifinal but was eventually defeated by Rainer Schüttler.
Roddick reached the semifinals of Wimbledon where he was defeated by Federer in straight sets but then won his maiden Masters Series title in Montreal, beating Federer in the semis on route. Roddick would then go on to win back to back Masters Series titles by winning Cincinnati.[4] At the US Open, Roddick saved a match point en route to the title in the semifinals against David Nalbandian, which he won 6–7(4–7), 3–6, 7–6(9–7), 6–1, 6–3. He went on to defeat Juan Carlos Ferrero 6–3, 7–6(7–2), 6–3 in the final.[5] Roddick became one of only three players to win Canada, Cincinnati and the US Open consecutively along with Patrick Rafter in 1998 and Rafael Nadal in 2013.
Juan Carlos Ferrero also added his name to the list of maiden Grand Slam champions in 2003 when he won the French Open, having lost in the final the previous year. He defeated surprise finalist Martin Verkerk 6–1, 6–3, 6–2. Ferrero also captured Masters Series titles in Monte Carlo and Madrid and went on to end the season as world No. 3.
Andre Agassi won his eighth and final Grand Slam title by defeating Rainer Schüttler in the final of the Australian Open 6–2, 6–2, 6–1. In March, Agassi won his sixth Miami Masters title and his 16th Masters title overall. On April 28, Agassi reclaimed his position at the top of the ATP rankings for the first time since 2000. He then replicated this feat when recapturing the No. 1 ranking on June 16, a position he maintained for 13 weeks. By being No. 1 in the rankings, he became the oldest world No. 1 at 33 years and 3 months of age, a record not broken till Federer got to the top of the rankings in 2018.[6] Agassi lost in the semifinals of the US Open to Ferrero.
Young Argentine Guillermo Coria had a breakout season in 2003, rising from world No. 45 in 2002 to 5 at the end of the year. He won his first Masters Series title in Hamburg and reached the semifinals of the French Open. Félix Mantilla caused an upset by capturing his first and only Masters title in Rome, picking up wins over Costa, Kafelnikov and Federer on the way. 4-time Wimbledon semi finalist Tim Henman also captured his lone Masters Series title by impressively coming through the draw in Paris, defeating the likes of Federer and Roddick on the way before defeating Andrei Pavel in the final.
2002 Wimbledon champion Lleyton Hewitt’s form dropped in 2003, losing his world No. 1 position and dropping out of the top 10. Despite failing to reach a Grand Slam semifinal in 2003, Hewitt did however defend the title at the Indian Wells Masters and was instrumental in helping Australia win the Davis Cup title. Hewitt defeated Federer in the semifinals from 2 sets down to help Australia reach the final. He then defeated Ferrero in the final in another 5 set victory to help Australia capture their 28th Davis Cup crown. Mark Philippoussis beat Ferrero to see Australia claim the victory over Spain 3–1 in Melbourne.
United States 16 (Australian Open, San Jose, Memphis, Delray Beach, Miami Masters, Houston, St. Poelten, London Queen's Club, Newport, Indianapolis, Canada Masters, Cincinnati Masters, US Open, Bangkok, Moscow and Stockholm)
Spain 10 (Viña del Mar, Buenos Aires, Monte Carlos Masters, Barcelona, Valencia, Rome Masters, French Open, Umag, Bucharest and Madrid Masters)
Argentina 7 (Acapulco, Hamburg Masters, Båstad, Stuttgart, Kitzbühel, Sopot and Basel)
Following is a list of notable players (winners of a main tour title, and/or part of the ATP rankings top 100 (singles) or top 50 (doubles) for at least one week) who announced their retirement from professional tennis, became inactive (after not playing for more than 52 weeks), or were permanently banned from playing, during the 2003 season:
Michael Chang (born February 22, 1972, in Hoboken, New Jersey) He turned professional in 1988 and reached a career-high ranking of world no. 2. He won the French Open in 1989 and was a finalist at the Australian Open and the US Open, as well as the year-end finals. In all, he won 34 career titles. He played his final career match at the US Open against Fernando González.[8]
Francisco Clavet (born October 24, 1968, in Aranjuez, Spain) He turned professional in 1988 and reached his career-high ranking of no. 18 in 1992. He earned eight singles titles and played his last match in Segovia in July against Nicolas Mahut.[9]
Fernando Meligeni (born April 12, 1971, in Buenos Aires, Argentina) He turned professional in 1990 and reached his career-high ranking of no. 25 in 1999. He reached the semifinals of the French Open in 1999 and earned three career singles titles. In doubles, he was ranked no. 34 in 1997 and earned seven career titles.
Andrea Gaudenzi (born 30 July 1973 in Faenza, Italy) He turned professional in 1990 and reached his career-high ranking of world no. 18 in 1995. He earned three career singles titles and two doubles titles. His last match was in San Marino in August against Federico Browne.[10]
Paul Haarhuis (born 19 February 1966 in Eindhoven, Netherlands) He turned professional in 1989 and reached a career-high ranking of world no. 18. He reached the quarterfinals at the US Open and earned one career singles title. In doubles, he was ranked world no. 1 in 1994 and won all four Grand Slam tournaments, the French open three times. He played his last career match at Wimbledon partnering Yevgeny Kafelnikov.[11]
Yevgeny Kafelnikov (born 18 February 1974 in Sochi, Soviet Union) He turned professional in 1992 and reached the world no. 1 ranking in 1999. He won two Grand Slam singles titles, the 1996 French Open and the 1999 Australian Open. He also won four Grand Slam doubles titles, and the men's singles gold medal at the Sydney Olympic Games in 2000. He also helped Russia win the Davis Cup in 2002. He is the last man to have won both the men's singles and doubles titles at the same Grand Slam tournament, the 1996 French Open. He played his last match in St. Petersburg in October against Mikhail Youzhny.[12]
Richard Krajicek (born 6 December 1971 in Rotterdam, Netherlands) He turned professional in 1989 and reached his career-high ranking of world no. 4 in 1999. He won Wimbledon in 1996 and was a semifinalist at the Australian and French Opens. He earned 17 career ATP titles. In doubles, he was ranked world no. 45 and won three career titles, also reaching the semifinals at the Australian Open. His last career ATP match was in 's-Hertogenbusch in June against Olivier Mutis.[13]
Alex O'Brien (born 7 March 1970 in Amarillo, Texas) He turned professional in 1992 and reached his career-high singles ranking of world no. 30 in 1997. He earned one career singles ATP title. In doubles, he was ranked world no. 1 in 2000 and won the US Open in 1999. He was a finalist at the Australian Open in 1996 and 1997 and a quarterfinalist at Wimbledon in 1999 and 2000. His last career match was in Torrance, California, in October partnering Kevin Kim.[14]
Sandon Stolle (born 13 July 1970 in Sydney, New South Wales, Australia) He turned professional in 1991 and reached a career-high singles ranking of no. 50 and doubles ranking of no. 2 in 2001. He earned 22 career titles in doubles and won the US Open in 1998, partnering Cyril Suk. He was a finalist at the US Open (1995), French Open (2000), and Wimbledon (2000), each time losing the final match to the "Woodies". His last match was at the Australian Open partnering Andrew Florent.[15]
Daniel Vacek (born 1 April 1971 in Prague, Czechoslovakia) He turned professional in 1990 and reached his career-high singles ranking of no. 26 in 1996. In doubles, he was ranked no. 3 in 1997 and earned 25 career titles. He won the French Open in 1996 and 1997 and the US Open in 1997. He was also a quarterfinalist at the Australian Open in 1999. He played his last match at Wimbledon partnering Jim Thomas.[16]
Adrian Voinea (born 6 August 1974 in Focşani, Romania) He turned professional in 1993 and reached his career-high ranking of world no. 36 in 1996. He reached the quarterfinals at the French Open in 1995 and earned one career ATP title. He played his last match in Sopot in July against Olivier Mutis.[17]
Roger Federer (7)
Andy Roddick (4,535)
Rainer Schüttler
Rafael Nadal
Mark Phillipoussis
Guillermo Coria
Michaël Llodra 
Nikolay Davydenko – Adelaide and Estoril (2)
Tim Henman – Washington, D.C., and Paris Masters (2)
Gustavo Kuerten – Auckland and St. Petersburg (2)
Nicolás Massú – Amersfoort and Palermo (2)
Sjeng Schalken – 's-Hertogenbosch and Costa do Sauipe (2)
Paradorn Srichaphan – Chennai and Long Island (2)
Wayne Ferreira – Los Angeles (1)
Stefan Koubek – Doha (1)
Karol Kučera – Copenhagen (1)
Hyung-Taik Lee – Sydney (1)
Max Mirnyi – Rotterdam (1)
Jiří Novák – Gstaad (1)
Andrea Gaudenzi (born 30 July 1973 in Faenza, Italy) He turned professional in 1990 and reached his career-high ranking of world no. 18 in 1995. He earned three career singles titles and two doubles titles. His last match was in San Marino in August against Federico Browne.[10]
Adrian Voinea (born 6 August 1974 in Focşani, Romania) He turned professional in 1993 and reached his career-high ranking of world no. 36 in 1996. He reached the quarterfinals at the French Open in 1995 and earned one career ATP title. He played his last match in Sopot in July against Olivier Mutis.[17]