Sun Ce (Chinese: 孫策; pinyin: Sūn Cè; Wade–Giles: Sun¹ Ts‘ê⁴) (pronunciation^ⓘ) (175 – 5 May 200), courtesy name Bofu, was a Chinese military general, politician, and warlord who lived during the late Eastern Han dynasty of China. He was the eldest child of Sun Jian, who was killed during the Battle of Xiangyang when Sun Ce was only 16. Sun Ce then broke away from his father's overlord, Yuan Shu, and headed to the Jiangdong region in southern China to establish his own power base there. With the help of several people, such as Zhang Zhao and Zhou Yu, Sun Ce managed to lay down the foundation of the state of Eastern Wu during the Three Kingdoms period.

In 200, when the warlord Cao Cao was at war with his rival Yuan Shao in the Battle of Guandu, Sun Ce was rumoured to be planning an attack on Xuchang, Cao Cao's base. However, he was assassinated before he could carry out the plan. Sun Ce was posthumously honoured as "Prince Huan of Changsha" (長沙桓王) by his younger brother Sun Quan when the latter became the founding emperor of Eastern Wu.

Chen Shou's Records of the Three Kingdoms (Sanguozhi) describes Sun Ce as a handsome man who was full of laughter. He was also a generous and receptive man who employed people according to their abilities. As such, his subjects were willing to risk their lives for him. One detractor named Xu Gong, in a letter to Emperor Xian, compared Sun Ce to Xiang Yu, the warrior-king who overthrew the Qin dynasty. As a result, Sun Ce was also referred to as the "Little Conqueror" in popular culture. Sun Ce is depicted in the Wu Shuang Pu (無雙譜, Table of Peerless Heroes) by Jin Guliang.

Born in 175, Sun Ce was the eldest son of Sun Jian, a military general serving under the Eastern Han dynasty. In 190, a year after Emperor Ling died, the warlord Dong Zhuo usurped power, placing in the throne the puppet Emperor Xian. Regional warlords in eastern China then launched a campaign against Dong Zhuo. Sun Jian rendered his service to Yuan Shu, one of the leaders of the coalition. The attempt to oust Dong Zhuo soon failed and China slid into a series of massive civil wars. In the next year, Sun Jian was sent by Yuan Shu to attack Liu Biao, governor of Jing Province, but he was killed in an ambush.

Sun Ce brought his father's body to Qu'e (曲阿; present-day Danyang, Jiangsu) for burial and settled his mother down before heading for Danyang, where his maternal uncle Wu Jing was the governor. There he raised a small militia a few hundred in strength. This small force was far from sufficient for him to establish his own power so in 194 Sun Ce went to Yuan Shu. Yuan Shu was very impressed with Sun Ce and often lamented that he had no son like him. He also returned Sun Jian's former division of troops to Sun Ce.

Initially, Yuan Shu promised to appoint Sun Ce the governor of Jiujiang but eventually gave the governorship to Chen Ji (陳紀). Later, when Yuan Shu was denied a large loan of grains from the governor of Lujiang, he sent Sun Ce to attack the latter, promising to make Sun Ce the governor of Lujiang should he succeed. When Sun Ce did, however, Yuan Shu again went back on his words and appointed someone else instead. The disappointed Sun Ce then began to contemplate leaving.

Meanwhile, Liu Yao, who was by imperial decree the governor of Yang Province, occupied Qu'e as the regional seat Shouchun was already occupied by Yuan Shu. He then forced Wu Jing back west across the Yangtze River to Liyang (歷陽; present-day He County, Anhui). However, Yuan Shu claimed to be the rightful governor and sent Wu Jing and Sun Ce's cousin Sun Ben to attack Liu Yao. After they were unable to break down Liu Yao's defences for more than a year, Sun Ce requested to lead forces to assist the effort.

Though Yuan Shu knew Sun Ce intended to leave, he believed the latter would not be able to defeat Liu Yao. Thus he deployed the young general off with merely a thousand odd troops and a tiny cavalry force. Along with a few hundred more willing followers, Sun Ce proceeded to Liyang, where he boosted his strength to more than 5,000. He then launched an offensive across the Yangtze River and successfully occupied the strategic position of Niuzhu (牛渚; southwest of present-day Ma'anshan, Anhui) in 195.