Yoshio Kodama (児玉誉士夫 Kodama Yoshio) (1911 — January 17, 1984) was a prominent figure in the rise of organized crime in Japan. He was a kuromaku who was involved from the 1950s to the early 1970s.

He lived in Korea early in his life, and during that time formed an ultranationalist group with the intent to assassinate various Japanese politicians. He was caught and served a jail term of three and a half years.

After his release, the Japanese government contracted Kodama to help move supplies for the Japanese war effort out of continental Asia and into Japan. He accomplished this through a network of allies he made during his time working in Korea as a youth. Kodama became involved in the drug trade at this time, moving opiates to Japan along with the supplies he was paid by the government to smuggle. He formed a vast network of allies and gained a fortune (more than $175 million dollars U.S., making him one of the richest men in Asia) during this time.

At the end of World War II, Kodama was arrested by the United States as a Class A war criminal. He was held in Sugamo Prison with Ryoichi Sasakawa, where the two formed a long friendship. While locked up, he wrote his "Sugamo Diary" (a chronicle of his experience in prison) and "I Was Defeated" (an autobiographical work).

The US intelligence community later secured his release in exchange for his aid in fighting Communism in Asia. Kodama, being a right-wing ultranationalist, eagerly obliged, using his fortune and network of contacts to quell labor disputes, root out Communist sympathizers, and otherwise fight socialist presence.

During this period, Kodama used his underworld connections to help unite the various gangs (which had greatly proliferated in the years immediately following World War II). The short-lived Kanto-kai was the most prominent example of these efforts.

Kodama was also involved in a number of scandals in the post-war era, many of which involved United States businesses and the CIA. Most notable of these was the 1970s Lockheed L-1011 sales scandal, which effectively marked the end of his career.

He died in his sleep of a stroke on January 17, 1984.