The 64-year-old soft-spoken centrist defeated popular vaccine chief Taro Kono in an unusually close race to succeed Prime Minister Yoshihide Suga, who decided to step down after just a year in office.
Kishida’s victory caps an unpredictable Liberal Democratic Party (LDP) election, in which two of the four candidates were female and most of the party’s largest factions allowed their members a free vote.
The LDP, which has been in power for all but about four years since 1955, will use its majority in parliament to formally install him as premier in a special session.
Kishida is widely regarded as a safe pair of hands, despite a low-key presence that has sometimes been characterized as a lack of charisma.
He has pledged to spend big on new pandemic stimulus while vowing to tackle income inequality and move away from the neo-liberal economics that has dominated Japanese politics for the past two decades.
Kishida previously served as LDP policy chief and was foreign minister between 2012-17, during which he negotiated accords with Russia and South Korea, with whom Japan’s relations are often frosty.
He has called abolishing nuclear weapons “my life’s work”, and in 2016 helped bring then-US president Barack Obama to Hiroshima on a historic visit.
Kishida entered politics in 1993, having previously worked at a bank as the Japanese economy boomed.