Noda is expected to be confirmed in parliament on Tuesday as the nation's sixth new premier in five years, replacing outgoing Naoto Kan who quit last Friday after his approval rating tumbled over his handling of the triple crisis.
Known as a fiscal hawk and a safe pair of hands rather than a charismatic leader, 54-year-old Noda has pledged a "middle-of-the-road" politics.
Noda emerged the winner of the five-way contest within the centre-left DPJ when he gained 215 votes in the second-round ballot, against 177 for the trade and industry minister, Banri Kaieda.
Speaking immediately after being elected president of the ruling Democratic Party of Japan (DPJ), Noda bowed deeply several times then pledged: "Gritting our teeth, let's create a stable, reliable and mature politics."
He promised to push for a speedy recovery from the March 11 disaster and its economic impact, and vowed to unite the deeply divided ruling party so that "everyone works together for the sake of the people."
Noda angered Japan's neighbours, including South Korea, weeks ago when he said on the anniversary of Japan's World War II surrender that Class-A war criminals convicted by an Allied tribunal were in fact not war criminals.
The son of a paratrooper in the Self-Defense Forces, Noda, a married father of two, holds broadly conservative views, opposing the granting of voting rights to ethnic Korean permanent residents living in Japan.