Gu Siyu (; born 11 February 1993) is a Chinese track and field athlete who competes in the discus throw and formerly the shot put. She holds a discus personal best of and a shot put best of . She was a double Asian junior champion in 2010 and represented her country at the 2013 World Championships in Athletics.
Gu began to make her first impact at the age of sixteen, when she took the discus title at the 2009 Australian Youth Olympic Festival.[1] She threw beyond fifty metres in the discus for the first time that year.[2] International medals followed at the 2010 Asian Junior Athletics Championships where she claimed a shot put/discus double for China.[3] She took the silver medal in the shot put later that year at the Summer Youth Olympics.[4]
The focus of her 2011 season was the Chinese City Games and she was the shot put runner-up behind Guo Tianqian, who was the world youth champion that year.[5] She was also runner-up in the discus competition and ended that tournament with improved bests of and in the throws.[6] Both these marks ranked her in the top five juniors globally that year.[7]
She marked herself as the best junior discus thrower in the country in 2012 by winning the Chinese junior championships with a big personal best of .[8] [9] She was far off this form at the 2012 World Junior Championships in Athletics and her best of nearly five metres less was only enough for fifth.[10]
Gu, dropping the shot put to focus on discus throwing instead, placed herself among the senior elite in the 2013 season. She began with a new best of on the Chinese Athletics Grand Prix circuit.[11] She travelled to compete in Germany in May and the 20-year-old surprised with a large throw of, raising her to second on the seasonal lists behind the dominant Sandra Perković.[12] [13] She earned her first senior selection for China as a result, but at the 2013 World Championships in Athletics she failed to register a valid mark and dropped out at the qualifying stage.[14] She had a quiet 2014, her best being a throw of in Jinan.[2]
| 2010 | Asian Junior Championships | Hanoi, Vietnam | bgcolor=gold | 1st | Shot put | |
| bgcolor=gold | 1st | Discus throw | ||||
| Youth Olympics | Singapore | bgcolor=silver | 2nd | Shot put | ||
| 2012 | World Junior Championships | Barcelona, Spain | 5th | Discus throw | ||
| 2013 | World Championships | Moscow, Russia | — | Discus throw | No mark |