Duke Ding of Qi (Chinese: 齊丁公; pinyin: Qí Dīng Gōng; reigned c. 10th century BC) was the second recorded ruler of the ancient Chinese state of Qi during the Western Zhou dynasty. His personal name was Lü Ji (呂伋) and ancestral name was Jiang (姜).^[1][2]

According to classical Chinese texts such as the Records of the Grand Historian and Zuo Zhuan, Duke Ding succeeded his father Lü Shang, Duke Tai of Qi, who was said to have been a centenarian. Duke Ding supposedly served King Kang of Zhou along with other major vassal state rulers including Xiong Yi, viscount of Chu, Count Kang of Wey (衞康伯), Xie, Marquis of Jin and Boqin, Duke of Lu. However, most modern historians believe Duke Ding was in fact the fifth-generation descendant of Duke Tai, and he could not have served King Kang of Zhou.^[3]

After Duke Ding died, he was succeeded by his son Duke Yǐ of Qi.^[1][2]

Wives:

• The mother of Crown Prince Dexing and Prince De

Sons:

• Prince Heng (公子衡), the progenitor of the Nie (聶) lineage
  • Served as the Minister of War of Wey
• Fourth son, Crown Prince Dexing (世子德興), the progenitor of the Cui lineage and the father of Count Mu of Cui (崔穆伯)
• Prince De (公子得; d. 933 BC), ruled as Duke Yǐ of Qi from 974–933 BC
• A son who ruled as the Count of Yi (懿)