Bu Xiangzhi (Chinese: 卜祥志; pinyin: Bǔ Xiángzhì; born December 10, 1985) is a Chinese chess player. In 1999, he became the 10th grandmaster from China at the age of 13 years, 10 months and 13 days, at the time the youngest in history. In April 2008, Bu and Ni Hua became the second and third Chinese players to pass the 2700 Elo rating line, after Wang Yue.

Bu was Chinese champion in 2004. He was a member of the gold medal-winning Chinese team at the 2015 World Team Chess Championship and at the 2018 Chess Olympiad.

Bu was born December 10, 1985, in Qingdao. At age six, Bu was first introduced to chess by an elder cousin (his grandfather was a strong xiangqi player), and his interest grew with his compatriot Xie Jun's women's world championship victory in 1991. He began taking chess seriously at the age of nine years and received early training from then on. During this time, the newspaper Qingdao Daily founded a local chess club which many children in the city went to, including the Qingdao Daily's chief editor's son. His first chess book was a translation of the famous My 60 Memorable Games by Bobby Fischer, a player Bu admires. By 1993, he had already won the Qingdao Junior Chess Championship.

In 1997 this talent became the children's champion of the National S.T. Lee Cup. In 1998 at the age of 12, he captured the titles of national pupil champion and under-14 world champion. In 1999 he finished seventh in the prestigious Tan Chin Nam Grandmaster Invitational Tournament.

A sponsorship contract with a mineral water producer of his home city Qingdao enabled to him in 1999 with his coach Ji Yunqi to travel to Europe to take part there in several international chess tournaments. In autumn 1999 he achieved within two months the required three norms for the title of Grandmaster (GM), with tournament wins at Paks GM tournament (6/9 points) in 21–29 September, at Kluger Memorial - First Saturday tournament (8+1⁄2/11 pts) in Budapest in 3–13 October, and coming joint first in the Qingdao Daily Cup (6/8 pts) in 18–23 October. He was 13 years, 10 months, and 13 days old when he scored the final norm, at the time the youngest person to achieve that title. His record as the world’s youngest grandmaster was broken by Sergey Karjakin in July 2002. Adding to his victories in 1999, he won the German Open.

In 2000 in Germany he won in his first appearance the International Neckar Open in Deizisau. Also in 2000, Bu defeated the Azerbaijani talent Teimour Radjabov 6+1⁄2-1½ in an eight-game Future World Champions Match competition in New York. They played two games a day at a time control of one hour for all the moves. The margin of victory was a little flattering to Bu with Radjabov missing a number of good chances on the first day and then having a bit of a disaster on day two losing both games. Radjabov had beaten Bu in the two game final of a Cadet's event held earlier in the year on the Kasparovchess.com site. In May 2000, Bu made his first appearance in a United States Chess Federation-rated tournament at the New York Open in New York City. Although one of the favorites to win the tournament, he lost in the first round to American life master Shearwood McClelland III in an upset, before rallying to finish with 5+1⁄2/9.

In December 2003, Bu won the 10th Aceimar International Open in Mondariz with 7+1⁄2/9.

In November 2004, he became National Chess Champion of China in Lanzhou with a score of 9/11.