Zhang Ao 張敖 (d. 182 BCE) was one of the regional rulers after the end of the Qin dynasty 秦 (221-206 BC). He was the son of Zhang Er 張耳 and participated in his father's campaigns against the last armies of the Qin.
The hegemonial king Xiang Yu 項羽 made his father King of Changshan 常山, but Zhang Er changed his loyalty to Liu Bang 劉邦, the eventual founder of the Han dynasty 漢 (206 BCE-220 CE) and was made King of Zhao 趙. In 202 Zhang Er died, and Zhang Ao succeded him to the throne of Zhao. He was married to Liu Bang's daughter, Princess Yuan of Lu 魯元公主 (posthumous title).
In 198 his plot to kill Liu Bang was reveiled, but he was pardoned and only demoted to Marquis of Xuanping 宣平侯. Zhang Ao's daughter became the wife of Emperor Hui 漢惠帝 (r. 195-188), her own uncle. Zhang Ao died under the reign of the Empress Dowager Lü 呂太后 (r. 188-180).
His posthumous title was Marquis Wu 武侯, but he was also venerated as King Yuan of Lu 魯元王.