The military veteran, who joined the army in 1975 and rose to the rank of general, received all 440 votes from the legislative body.
In his inauguration speech, Cuong pledged to build a prosperous country, pursue an independent and self-reliant foreign policy and strengthen national defense and security."
His term will last until the Communist Party congress in 2026.
The appointment represents a careful balance of power between military and public security forces in Viet Nam's leadership, according to experts.
The country's four pillars of power now consist of Communist Party General Secretary Vo Van Thuong, President Cuong, Prime Minister Pham Minh Chinh, and the National Assembly chairperson, with Cuong's position ranked second in the national hierarchy.
Nguyen Khac Giang, a Viet Nam specialist at Singapore's ISEAS-Yusof Ishak Institute, described the appointment as "a careful attempt to restore the balance between military and public security forces" and "a move to stabilize the system."
The leadership change comes after several high-ranking officials stepped down amid an anti-corruption campaign, with analysts expecting Cuong's appointment to bring some political stability to Viet Nam.