Born on May 4, 1918, the eldest son of the poor farmer Tanaka Kakuji in Futada, Kariwa District, Niigata (today Kashiwazaki). With only the local Futada Ordinary Higher Elementary School to his name, he went up to Tokyo, worked in the civil-engineering and construction trade, learned civil engineering design by self-study, and at 19 founded Tanaka Doken Kogyo. During the war he expanded civil-engineering business in the Korean Peninsula and made his fortune. In 1947 he was first elected to the House of Representatives from Niigata 3rd district as a Japan Progressive Party endorsee (at 28). Thereafter he was elected for 16 consecutive terms. He served as minister of post and telecommunications in the First Kishi Cabinet in 1957 (at 39), as finance minister in the Ikeda Cabinet in 1962, and as minister of international trade and industry in the Third Sato Cabinet in 1971, and held four terms as LDP secretary-general. On July 7, 1972, he took office as the 64th prime minister at 54, called the 'Today's Taiko.' On September 25 of that year he visited China, and on September 29 in Beijing signed the Japan-China Joint Communique, realizing the normalization of Japan-China relations. He proclaimed the 'Plan for Remodeling the Japanese Archipelago' and pushed massive public investment to break the concentration in the Pacific Belt, but he brought on the first oil shock (1973) and runaway prices, and stepped down in December 1974. On July 27, 1976, he was arrested in the Lockheed Affair on charges of taking a 500 million yen bribe. He received prison sentences in the first and second trials, but on appeal, on December 16, 1993, at Keio Hospital in Shinanomachi, Tokyo, he died of thyroid dysfunction at 75, and the prosecution was dismissed.

An energetic, friendly, born winner-of-people politician. He had an astonishing brain that memorized figures and personal names so well that he was called the 'memo demon.' He was assessed as a 'bulldozer with a computer attached.' Because he rose by his own ability without relying on academic credentials, he was also liked by bureaucrats. He remembered petitioners down to 'arrival in Tokyo at this time, departure for home at that time' and was known for the firm sense of obligation that 'I promised you this then' and surely carried it out. Open-hearted and a strong drinker, he had a hoarse voice and 'yossha yossha' as his pet phrase.

The normalization of relations with China is highly evaluated to this day as the greatest historical achievement of Tanaka politics. The idea of the 'Plan for Remodeling the Japanese Archipelago' built the foundation of postwar infrastructure as regional dispersion, the Shinkansen network, and the expressway network, while it also produced the ills of land-price spikes, dependence on public works, and pork-barrel politics. The Lockheed Affair became a symbol of distrust in politics as the largest corruption case of the postwar era; on the other hand, the Kakuei boom after Tanaka's death (especially since the 2010s) has continued a re-evaluation of him as 'the people's premier' and 'a politician of decision.' The 'Tanaka faction' and 'Keiseikai,' the largest factions, produced Takeshita Noboru, Hashimoto Ryutaro, Obuchi Keizo, Ozawa Ichiro, and others. Near Tanaka's birthplace in Kashiwazaki, Niigata, the Tanaka Kakuei Memorial Hall has been built. His daughter Tanaka Makiko also served as foreign minister.