Fan Yilin was born on 11 November 1999 in Taizhou, Zhejiang. Her father, Fan Bingzhu, is a former professional wrestler. Fan began gymnastics at the age of six in order to improve her health since she had been ill as a child.
Junior career
In 2013, Fan represented Zhejiang in the 1999-2000 Junior National Championships. The team won gold overall, and Fan placed fifth in the uneven bars final. At the 2013 Chinese National Games, Fan won team gold again and placed fourth on uneven bars. She did not compete in 2014 due to injuries.
Senior career
2015
Fan's senior career started in 2015. At the Chinese National Championships in May, Fan won gold in uneven bars final, ahead of world champion Huang Huidan In addition, she won silver with the Shanghai team and placed third on balance beam. She later made her senior international debut as a member of the Chinese team at the 2015 Asian Championships in Hiroshima, Japan, where she won gold on balance beam, silver with the team, and bronze on uneven bars. She was selected to compete at the World Championships in Glasgow, Scotland alongside Shang Chunsong, Wang Yan, Mao Yi, Tan Jiaxin, Chen Siyi, and Zhu Xiaofang. They won the silver medal behind the United States team. Individually, after qualifying in fifth-place, Fan won gold on uneven bars in the first ever four-way tie along with Viktoria Komova, Daria Spiridonova, and Madison Kocian. "It made me laugh to see four gymnasts with the same score, but I'm happy for all of the other gold medalists," Fan said.
2016
Fan competed at the Chinese National Championships in May, and she won gold on uneven bars with a 0.434 lead, and she placed sixth on beam. At the conclusion of the Chinese Championships, Fan was named to the Chinese team for the 2016 Summer Olympics along with Shang Chunsong, Mao Yi, Wang Yan, and Liu Tingting.
Fan competed in the women's qualification round at the 2016 Summer Olympics on August 7, scoring 15.266 on bars, 14.866 on beam, and 13.500 on floor exercise. She helped the Chinese team qualify into the team final in second place behind the United States. Individually, Fan qualified sixth into the balance beam final. Controversially, Fan failed to qualify for the uneven bars final placing ninth due to missing some connections in her routine. Her countrywoman Shang Chunsong qualified ahead of her by 0.034. On August 9, in the team final, Fan competed on the uneven bars and the balance beam, contributing 15.733 and 15.066 respectively to China's third-place finish behind the United States and the Russian teams. Fan placed sixth in the balance beam final on August 15 with a score of 14.500.
2017
Fan competed at the National Championships, placing third on the uneven bars and seventh on balance beam. She was not named to the team competing at the Asian Championships. However, she performed well at the National Games later in the year and won gold on uneven bars. She was named to the team roster to compete at the World Championships along with Liu Tingting, Luo Huan, and Wang Yan. In the qualifying round at the World Championships, Fan qualified into the uneven bars final in third place and successfully landed her original dismount, after which it was named after her in the Code of Points. Fan won the uneven bars final with a 15.166 ahead of Elena Eremina of Russia and Nina Derwael of Belgium after upgrading from the first day of competition to have the highest difficulty score in the final. With this victory, she became the first Chinese woman and the fourth overall gymnast in history to defend their World uneven bars title after Maxi Gnacuk, Daniela Silivas, and Svetlana Khorkina.
2018
Fan did not compete for much of the year, missing both the Chinese National Championships in the spring and the Asian Games in August. However, she competed at the Individual National Championships where she won gold on the uneven bars. Despite this result, she was not chosen to compete at the World Championships. Because she missed the World Championships, she became eligible to qualify an individual nominative spot to the 2020 Summer Olympics in Tokyo, Japan as the winner of the 2018-2020 FIG Individual Apparatus World Cup series on the uneven bars, based on the new qualification rules introduced following the 2016 Summer Olympics. Fan returned to international competition at the Cottbus World Cup, where she qualified in first place to the uneven bars final ahead of new world champion Nina Derwael; however, in the final, she fell on her eponymous dismount and placed eighth.
2019
Fan was selected to compete at the Melbourne World Cup alongside countrywoman Lyu Jiaqi, who she beat to win gold in the uneven bars final. She later competed at the Doha World Cup in March where she qualified to the uneven bars final in second place behind Nina Derwael. In the event finals, she once again placed second behind Derwael.
2020
Fan competed at the Baku World Cup where she finished first on uneven bars during qualifications and qualified to the event final. However event finals were canceled due to the 2020 coronavirus outbreak in Azerbaijan.
