Gu Siyu (Chinese: 谷思雨; 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 67.86 m (222 ft 7+1⁄2 in) and a shot put best of 16.59 m (54 ft 5 in). She was a double Asian junior champion in 2010 and represented her country at the 2013 World Championships in Athletics.