Mibuchi Shinzaburō (三淵 震三郎, 11 April 1911 – 20 March 1989) was a Japanese businessman who was in the insurance industry.
Shinzaburō was born in Fukushima in 1911, as the third son of Mibuchi Tadahiko, who was a Catholic Christian, a former court judge and worked for the Sumitomo Trust.
His younger sister Tama married Ishiwatari Shingorō, the son of Ishiwatari Bin'ichi [ja], the prominent jurist and a public prosecutor of the Supreme Court of Judicature of Japan, and who worked for the Tokyo Kasai Hoken (The Tokyo Fire Insurance) before becoming the senior official of the Manchukuo Government.
[1] Shinzaburō joined the Dai Tokyo Kasai Kaijo Hoken (Dai-Tokyo Fire and Marine Insurance) in 1941, and was soon promoted to the head of the collection department.
Shinzaburō later served as the managing director of the General Insurance Rating Organization of Japan.