Zhang Yan, né Chu Yan (褚燕), also known as Zhang Feiyan (張飛燕), was the leader of the Heishan bandits during the late Han Dynasty period of Chinese history. He was a native of Zhending, Changshan commandery (modern Baoding).
He was born Chu Yan. Because he was fast, and agile, and brave, his men called him "Feiyan", meaning "Flying Swallow".
Not much was known about him historically until 185, when he and Zhang Niujue (張牛角), another bandit leader, raided the town of Yingtao (癭陶). Zhang Niujue was killed, but before he died, he ordered his men to obey Feiyan as their new leader. Yan thus changed his surname to Zhang to honour Zhang Niujue.
His force steadily grew in strength, until they were said to be a million in number. They became known as the Heishan bandits. All the commanderies north of the Yellow River were exposed to their attacks and the court could do nothing to stop them.
In 193, Zhang Yan fought to a stalemate against Lü Bu – who at the time was serving nominally under Yuan Shao and undertook his quest to pacify various regions neighboring the Taihang Mountains.
In 199, he responded to Gongsun Zan's request for help in the Battle of Yijing. Before he arrived, Gongsun Zan was destroyed by Yuan Shao.
In 204, he made contact with Cao Cao, who at the time was warring against Yuan Shao's sons Yuan Tan and Yuan Shang. Cao Cao appointed him General Who Pacified the North (平北將軍).
In the summer of 205, after the Yuans were destroyed, Zhang Yan officially surrendered to Cao Cao and was made Marquis of Anguo Village (安國亭侯).