Jelena Janković (Serbian Cyrillic: Јелена Јанковић, pronounced ; born February 28, 1985 in Belgrade) is a former World No. 1 professional tennis player from Serbia. She reached the final of the 2008 US Open and won the 2007 Wimbledon Mixed Doubles title. Janković is ranked World No. 12, being coached by the former ATP top 15 player, Andrei Pavel.
Janković was born in Belgrade, Serbia, Yugoslavia, as the third child of Veselin and Snežana, two economists.. She has two brothers, Marko and Stefan. She is a student at the Megatrend University in Belgrade, studying economics; however, she has put her course of study on indefinite hold as she continues to pursue her tennis career. Janković learned her first tennis skills at the Tennis Club 'Red Star'. As a nine-and-a-half year old she was introduced to tennis by her elder brother and fitness coach Marko. With 11 years has won the national championship in the competition to 12 years. She was later trained at the Tennis Academy of Nick Bollettieri. As a junior she won the 2001 Australian Open and junior No. 1 in the world. In 2001, she started to play on the WTA Tour; she reached the second round at her first tournament at the Indian Wells Masters.
In October 2003, Janković entered the top 100 at No. 90 for the first time after winning her first ITF title in Dubai. Three months later, Janković garnered her first top 10 win against Elena Dementieva 6–1, 6–4 in the first round of the 2004 Australian Open. In May, Janković won her first WTA title, a Tier V event, in Budapest, defeating Martina Suchá in the final 7–6, 6–3. Following her win in Budapest, she reached No. 51 in the world. Elsewhere in her 2004 season, she defeated top 20 players Nadia Petrova (twice), Vera Zvonareva, Patty Schnyder and Paola Suárez. Janković finished 2004 ranked No. 28 in the world.