Born in Hiroshima Prefecture, Ikeda studied law at Kyoto Imperial University and entered the Ministry of Finance in 1925, working there for the next two decades.

After the war, he was first elected to the National Diet in 1947 and served as finance minister from 1949 to 1952 under Shigeru Yoshida, being responsible implementing an economic stabilization program.

During his tenure, Ikeda worked to repair the rift in U.S.–Japan relations and to ease the domestic political divisions which had been exacerbated by the recent protests, played an important role in settling the Miike Struggle, and oversaw the successful 1964 Olympic Games before resigning due to ill health.

In a December 1950 Upper House Budget Committee meeting, for example, Ikeda suggested that poor people should eat more barley, rather than expensive white rice.

"[4] Ikeda then became Minister of International Trade and Industry following a cabinet reshuffle in 1952, but was forced to resign less than one month later after he was reported to have said in the Diet, in reference to efforts to curb rampant inflation, "even if five or ten small businessmen commit suicide, it can't be helped.

Ikeda was elected president of the LDP and became Prime Minister in July 1960, at an extremely difficult moment in Japanese domestic politics and U.S.-Japan relations.

[6] Although Kishi was ultimately successful in ramming the revised treaty through the Diet, the size and violence of the protests that followed forced him to cancel a planned visit by U.S. president Dwight D. Eisenhower and resign in disgrace.

Ikeda's new image and Income Doubling Plan proved popular,[8] and he won a resounding victory at the polls in the fall, leaving no chance that one of his factional rivals in the LDP could replace him.

[12] Ikeda also relentlessly pushed Japanese trade abroad, in support of his goal to expand export-led economic growth under the Income Doubling Plan.

[22] However, it also severely damaged the electoral prospects of the opposition Japan Socialist Party going forward, as the JSP had previously been able to win votes by pointing out that they needed at least one-third of the seats in the Diet to block the LDP's attempts at revising the Constitution.

Hoping to avoid a vicious intra-party struggle to succeed him, Ikeda took the unusual step of personally designating Eisaku Satō as his successor.

Ikeda's longstanding rival Ichirō Kōno respected his dying wish and declined to run for party president, clearing the way for Satō to succeed to the premiership.

[25] As faction leader, he was succeeded in turn by Shigesaburō Maeo, Masayoshi Ōhira, Zenkō Suzuki, Kiichi Miyazawa, Koichi Kato, Mitsuo Horiuchi, Makoto Koga, and Fumio Kishida.

Historian Nick Kapur credits Ikeda with stabilizing the "1955 System" in Japanese politics, after it nearly came apart amid vicious factional infighting within the LDP during the 1960 Security Treaty crisis.

[27] Ikeda's Income Doubling Plan also proved to be an astonishing success, helping greatly extend the lifespan of Japan's postwar "economic miracle."

"[29] Similarly, Japanese economist Takafusa Nakamura concluded that "Ikeda was the single most important figure in Japan's rapid [economic] growth.