Si Jiahui

 ( 2002 Births ) 

Si entered a nine-ball tournament in Shanghai for elementary school students, where he was runner-up. At the tournament, his father met another father whose son was training at a snooker academy in Guangdong. In September 2013, aged 11, Si left school and moved to Guangdong, accompanied by his father, where he began playing snooker. At age 12, he began training at the Wiraka Billiard Academy in Foshan, where he was coached by Roger Leighton. At 14, he defeated former world number one Ding Junhui 3–2 in a national tournament.

At age 16, Si moved to the United Kingdom. He joined Victoria’s Snooker Academy in Sheffield, a stable of mostly Chinese players managed by former snooker journalist Victoria Shi. Other players at the Academy upon Si's arrival included Zhao Xintong, Yan Bingtao, and Fan Zhengyi.

Si spent the 2021–22 season competing as an amateur, but earned top-up places in ranking tournaments through his high placement in the 2021 Q School Order of Merit. At the 2021 UK Championship, he defeated former world champion Shaun Murphy 6–5 in the first round. In a BBC radio interview after the match, Murphy objected to amateur players featuring in professional events, saying that he had "lost to someone who shouldn’t even be in the building". The World Snooker Tour issued a statement disagreeing with these remarks, and Murphy subsequently apologised for "taking the shine off" Si's win.

Towards the end of the season, Si won the 2022 World Snooker Federation Open amateur event, defeating Lee Stephens 5–0 in the final. This win earned him a two-year professional tour card for the 2022–23 and 2023–24 seasons. At the 2022 European Masters, he defeated Anthony McGill and Daniel Wells to reach his first quarter-final at a ranking event, which he lost 2–5 to Kyren Wilson.

Ranked 80th in the world rankings, he qualified for the main stage of the 2023 World Snooker Championship after defeating Florian Nüßle 10–7, Tom Ford 10–5, and Jordan Brown 10–7 in the qualifying rounds. In the first round at the Crucible Theatre, Si defeated Murphy 10–9. On this occasion, Murphy commented on how well Si had played, saying he had been "fabulous". Si defeated Robert Milkins 13–7 in the second round and McGill 13–12 in the quarter-finals, becoming the first Crucible debutant to reach the World Championship semi-finals since Andy Hicks in 1995 and the youngest player to do so since Ronnie O'Sullivan in 1996. Si lost 15–17 to Luca Brecel in the semi-finals after Brecel, from 5–14 down, won 12 of the last 13 frames. Si advanced from 80th to 36th in the world rankings as a result of his performance at the tournament.

Si reached the first ranking final of his career at the following season's 2024 German Masters, but lost 5–10 to Judd Trump. At the 2024 World Championship, he defeated Mark Williams 109 in the first round and then lost 913 to Jak Jones in the last 16. The 2025 Masters marked his first appearance at the tournament, but Si lost in the first round to Mark Allen 26. At the 2025 World Championship, Si advanced to the quarter-finals where he was defeated by O'Sullivan 913.