Vietnam President Tran Dai Quang, one of the country's top three leaders but with mostly ceremonial duties, died on Friday after an illness, state television and radio announced.
Quang, 61, died in a military hospital in Hanoi from a "serious illness despite efforts by domestic and international doctors and professors", Vietnam Television reported.
Vietnam has no paramount ruler and is officially led by the president, prime minister and Communist Party chief. Experts say the presidency is largely ceremonial.
Quang was appointed to the role in April, 2016. Before that, he had served as minister of public security, an organisation with broad powers and a remit that includes intelligence gathering and thwarting domestic and foreign threats to the party.
Originally from a small farming community 115 kilometres south of Hanoi, Quang rose through party ranks to become a police general and member of Vietnam's powerful decision-making Politburo.
"We are saddened to hear the news that the president has died," said Bui Duc Phi, chairman of the village in which Quang was born.