She was also elected chair of the National Electoral Council.
The 62-year-old native of Ben Tre took the oath of office at a ceremony on March 31 immediately after her election where she pledged allegiance to the motherland, people and constitution of the Socialist Republic of Vietnam.
The new National Assembly speaker said she vowed to work hard to fulfil the duties entrusted by the Party, State and people.
Ngan was born in 1954 in the southern province of Ben Tre’s Giong Trom district and joined the Communist Party of Vietnam in 1991.
She was elected to the Politburo at the 7th plenary meeting of 11th Party Central Committee in 2013 and re-elected to the Politburo by the 12th Central Committee in January this year.
The posts she held previously include Deputy Minister of Finance, Deputy Minister of Commerce, Minister of Labour, Invalids and Social Affairs, and Vice Chair of the National Assembly.
On March 30, the majority of the parliament voted to dismiss Nguyen Sinh Hung from both positions as Chairman of the National Assembly and the National Electoral Council.