Zhang Jun (張駿 Zhāng Jùn; 307–346), courtesy name Gongting (公庭), formally Duke Zhongcheng of Xiping (西平忠成公, posthumous name given by Jin Dynasty) or Duke Wen of Xiping (西平文公, posthumous name used internally in Former Liang) was a ruler of the Chinese state Former Liang. During his reign, he at times used the Jin-created title of Duke of Xiping, but when forced to submit to Han Zhao and Later Zhao, he used the title Prince of Liang. Late in his reign, even when not under Later Zhao's pressure, he claimed the title of "Acting Prince of Liang." During the brief reign of his son Zhang Zuo, he was honored as Prince Wen of Liang (涼文王). The Book of Jin describes Zhang Jun as having an extraordinary appearance and was talented at literature, however he was also an extravagant and dissipated man.