They only need to furnish a negative PCR test result and monitor their health for 10 days, according to new regulations effective from April 29, the Japanese Ministry of Foreign Affairs said.
Those without proof of triple vaccination have to undergo seven-day home quarantine but can end it if they test negative on the third day.
The Japanese government had required travelers from Vietnam to quarantine for three days at a government-designated facility since July last year regardless of vaccination status.
Vietnam resumed commercial flights to and from Tokyo early this year.