Duke You of Lu

Duke You of Lu (Chinese: 魯幽公; pinyin: Lǔ Yōu Gōng), personal name Ji Zai (姬宰), was the fourth ruler of the State of Lu during the Western Zhou dynasty of ancient China. He was a member of the royal Ji family, the son of the previous ruler, Duke Yang of Lu, and the grandson of the state's founder, Bo Qin.

Duke You of Lu's reign is recorded as having lasted for fourteen years. However, this period ended tragically, as historical records state he was murdered by his younger brother, Ji Wei. Following this assassination, Ji Wei usurped the throne and became the next ruler, known posthumously as Duke Wei of Lu. As with his predecessors who ruled during the early Western Zhou period, specific details regarding the administrative actions or significant events of Duke You's time in power are extremely scarce in surviving historical documents.