Cai Gongshi (; 1 May 18813 May 1928) was a Chinese nationalist politician and diplomat.

Born in Jiujiang, Jiangxi, Cai studied economics and politics at Imperial University in Tokyo, Japan, earning a master's degree. Upon his return to China, he joined Sun Yat-sen's Kuomintang (KMT), and later served in various roles in the Chinese nationalist government. In 1927, he was appointed Superintendent of Customs and Commissioner of Foreign Affairs in Nanjing. On 1 May 1928, he was appointed Commissioner of Foreign Affairs for Shandong province, and was tasked with negotiating for Japanese withdrawal from the province. He was subsequently killed on 3 May by Japanese soldiers during the Jinan incident. According to Chinese sources, the Japanese soldiers broke his leg, smashed his teeth, cut out his tongue, and shot him.An Xiang: "Second Northern Expedition 1928: Part II" 16 other members of his negotiation team were also mutilated and killed on the same day.

The Cai Gongshi Memorial Hall, based out of the government building in which Cai was killed, was opened in his name on the 84th anniversary of the Jinan incident in 2012, recognising Cai as "China's first anti-Japanese martyr". The opening was attended by his daughter Cai Jinming and his son Cai Jinren, the latter of whom travelled from his home in Taiwan for the ceremony.

References