Emperor An of Han (Chinese: 漢安帝; pinyin: Hàn Āndì; Wade–Giles: Han An-ti; 94 – 30 April 125) was an Emperor of the Han dynasty and the sixth emperor of the Eastern Han, ruling from 106 to 125. He was a grandson of Emperor Zhang and cousin to Emperor Shang of Han, who died while Deng Sui, the empress dowager, served as regent.

When her infant stepson Emperor Shang succeeded to the throne in February 106, Empress Dowager Deng kept the then-12-year-old Crown Prince Liu Hu in the capital Luoyang as insurance against the infant emperor's death and the successor to the throne. Prince Hu ascended the throne and became emperor when Emperor Shang died in September 106. However, Empress Dowager Deng still remained as regent until her death in April 121. Thereafter, Emperor An removed many of her relatives from government and many of them committed suicide, probably under duress.

Emperor An did little to revive the withering dynasty. He began to indulge himself in women and heavy drinking and paid little attention to affairs of state, instead leaving matters to corrupt eunuchs. In this way, he effectively became the first emperor in Han history to encourage corruption. He also trusted his wife Empress Yan Ji and her family deeply, despite their obvious corruption. Unfortunately, the alliance of rival factions within the palace, formed to pursue larger political goals and preserve their power, nearly led to disaster; for example, the removal of Liu Bao (Prince Bao, who later became known as Emperor Shun) from the position of crown prince. His mother, Lady Li, had previously been killed by poisoning by Empress Yan Ji. At the same time, droughts ravaged the country while peasants rose up in arms. In April 125, Emperor An died while travelling to Nanyang. He was only 31.

Then-Prince Hu was born in 94, to Prince Liu Qing of Qinghe and his concubine, Consort Zuo Xiao E (左小娥). Prince Qing was the older brother of Emperor He, and had once been crown prince under their father, Emperor Zhang, until the machinations of Emperor Zhang's wife, Empress Dou, led to his removal and his mother Consort Song's death. During Emperor He's reign, however, he was a trusted advisor to the emperor, and he had a major role in Emperor He's coup d'état against Empress Dou's domineering brother, Dou Xian, in 92.

When they were young, consort Zuo and her older sister Da E (左大娥) were both confiscated and made court servant girls because their uncle, Zuo Sheng (左聖), had been executed for making defamatory remarks against the emperor or imperial administration. As they grew older, they became known for beauty and talent and became ladies in waiting in Emperor He's palace; Xiao E was particularly known for her knowledge in history and poetry. At Prince Qing's request, Emperor He rewarded him with the two consorts. Both died sometime before Emperor He's death in 106 and were buried in the capital Luoyang. After Consort Zuo's death, Prince Hu was raised by Prince Qing's wife, Consort Geng (耿姬).

When Emperor He died in 106, his infant son, Emperor Shang, ascended the throne. Most of Emperor He's brothers, including Prince Qing, remained in the palace at Luoyang but were ordered to report to their principalities. As an insurance measure, Emperor He's wife, Empress Dowager Deng, kept Prince Qing's wife and 12-year-old son (Prince Hu). When Emperor Shang died later in 106, the officials largely wanted to make Emperor Shang's brother, Prince Sheng (劉勝) of Pingyuan, emperor. However, Empress Deng had initially denied Prince Sheng the throne because she believed him to be frequently ill; she was concerned that he would bear a grudge against her. At her insistence, Prince Hu ascended the throne as Emperor An.

After Emperor An ascended the throne, however, the real power remained in Empress Dowager Deng's hands. She sent Consort Geng to join her husband in the Principality of Qinghe (in modern central Hebei) so that Emperor An had no real influence on the administration.

Empress Dowager Deng was generally a capable ruler. While there were natural disasters and wars with Qiang and South Xiongnu, she generally coped with those emergencies well. She also carried out many criminal law reforms. During her regency, Emperor An appeared to have minimal input into the affairs of state. Meanwhile, he became heavily personally influenced by the eunuchs Jiang Jing (江京) and Li Run (李閏), and even more so by his wet nurse Wang Sheng (王聖). He was especially heavily influenced by his favorite consort, Empress Yan Ji (閻姬). He made Yan Ji empress in 115, even though she had poisoned one of his other consorts, Consort Li, who had given birth to his only son Liu Bao (劉保) earlier that year. While these people lacked real power as long as Empress Dowager Deng lived, they were planning to take power as soon as she was no longer on the scene. Empress Dowager Deng was somewhat aware of these plans and was offended; she was also disappointed that Emperor An, who was considered a precocious and intelligent child, had neglected his studies and became only interested in drinking and women. It is suspected that at some point, she even considered replacing the emperor with his cousin Liu Yi (劉翼), the Prince of Pingyuan. However, she eventually decided against it.