Hong Xiuquan (1 January 1814 – 1 June 1864), born Hong Huoxiu and with the courtesy name Renkun, was a Chinese revolutionary and religious leader who led the Taiping Rebellion against the Qing dynasty. He established the Taiping Heavenly Kingdom over large portions of southern China, with himself as its "Heavenly King".

Born into a Hakka family in Guangzhou, Hong claimed to have experienced mystical visions after failing the imperial examinations. He came to believe that his celestial father, whom he saw in the visions, was God the Father, his celestial elder brother was Jesus Christ, and he had been directed to rid the world of demon worship. He rejected Confucianism and began propagating a fusion of Christianity, Daoism and millenarianism, which Hong presented as a restoration of the ancient Chinese faith in Shangdi. His associate Feng Yunshan then founded the God Worshipping Society to spread Hong's teachings. By 1850, Hong's sect had over 10,000 followers and increasingly came into conflict with Qing authorities.

In January 1851, Hong organized a rebel army and routed the Qing forces at Jintian, marking the beginning of the Taiping Rebellion. He then declared himself the Heavenly King of the Heavenly Kingdom of Peace. Taiping rebels captured the city of Nanjing in March 1853 and declared it the Heavenly Capital of the kingdom, after which Hong withdrew to his new palace and began ruling through proclamations. He became increasingly suspicious of Yang Xiuqing, his fellow Taiping leader, and engineered Yang's murder in a 1856 purge that spiraled into the further purge of more Taiping leaders. The kingdom gradually lost ground and in June 1864, in the face of Qing advance, Hong died following a period of illness and was succeeded by his son, Hong Tianguifu. Nanjing fell a month later.

Hong Xiuquan, born "Hong Huoxiu", was the third and youngest son of a Hakka family living in the village of Fuyuan Springs (also referred to as Fuyuanshui village), Hua county (now part of Huadu District) in Guangzhou. His father was Hong Jingyang, a farmer and elected headman and his mother was surnamed Wang. No less than nine different dates are given for Hong Xiuquan's birth: Jian Youwen established based on documentary evidence that Hong was born on 1 January 1814. This date is accepted by most scholars, including noted Chinese historian Luo Ergang. Some sources claim his family was "well to do". He and his family moved to Guanlubu Village shortly after his birth. Upon marrying his wife Lai Xiying, Hong received the courtesy name "Renkun." His sister, Hong Xuanjiao, became the commander of the female battalion during the Taiping Rebellion.

Hong showed an interest in scholarship at an early age, so his family made financial sacrifices to provide a formal education for him, in the hope that he could one day complete all of the civil service examinations. Hong began studying at a primary school in his village at the age of five. He was able to recite the Four Books after five or six years. He then took the local entry-level civil service examinations and placed first. A few years later, he traveled to the provincial capital of Guangzhou to take the provincial examinations. He was unsuccessful and, his parents being unable to afford to continue his education, he was forced to return to agricultural work. The next year, he accompanied a wealthy schoolmate elsewhere for a year of study and became a village schoolteacher upon his return.

In 1836, at the age of 22, Hong returned to Guangzhou to retake the imperial examinations. While in Guangzhou, Hong heard Edwin Stevens, a foreign missionary, and his interpreter preaching about Christianity. From them, Hong received a set of pamphlets entitled "Good Words for Exhorting the Age", which were written by Liang Fa, Stevens's assistant, and contained excerpts from the Bible along with homilies and other material prepared by Liang. Supposedly, Hong only briefly looked over these pamphlets and did not pay much attention to them at the time. Unsurprisingly, he again failed the imperial examinations, which had a pass rate of less than one percent.

In 1837, Hong attempted and failed the imperial examinations for a third time, leading to a nervous breakdown. He was delirious for days to the point that his family feared for his life. While convalescing, Hong dreamed of visiting Heaven, where he discovered that he possessed a celestial family distinct from his earthly family, which included a heavenly father, mother, elder brother, sister-in-law, wife, and son. His heavenly father, wearing a black dragon robe and high-brimmed hat with a long golden beard, lamented that men were worshiping demons rather than he himself, and presented Hong with a sword and golden seal with which to slay the demons infesting Heaven. Furthermore, he did so with the help of his celestial older-brother and a heavenly army. The father figure later informed Hong that his given name violated taboos and had to be changed, suggesting as one option the "Hong Xiuquan" moniker ultimately adopted by Hong. In later embellishments, Hong would declare that he also saw Confucius being punished by Hong's celestial father for leading the people astray. His acquaintances would later claim that after awakening from his dreams Hong became more careful, friendly, and open, while his pace became imposing and firm and his height and size increased. Hong stopped studying for the imperial examinations and sought work as a teacher. For the next several years Hong taught at several schools around the area of his hometown.

In 1843, Hong failed the imperial examinations for the fourth and final time. It was only then, prompted by a visit by his cousin, that Hong took time to carefully examine the Christian pamphlets he had received. After reading these pamphlets, Hong came to believe that they had given him the key to interpreting his visions: his celestial father was God the Father (whom he identified with Shangdi from Chinese tradition), the elder brother that he had seen was Jesus Christ, and he had been directed to rid the world of demon worship. This interpretation led him to conclude that he was the literal son of God and younger brother to Jesus. In contrast to some of the later leaders of his movement, Hong appears to have genuinely believed in his ascent to Heaven and divine mission. After coming to this conclusion Hong began destroying idols and enthusiastically preaching his interpretation of Christianity. As a symbolic gesture to purge China of Confucianism, he and the cousin asked for two giant swords, three chi (1 meter (3.3 ft)) long and nine jin (about 4.5 kg), called the "demon-slaying swords" (斬妖劍), to be forged.