Hanoi rose 41 places to 76th while HCMC jumped 30 places to 52nd in the ranking of 100 most popular city destinations this summer, based on flight search data for July and August this year.
This year's biggest improver was Taipei, which rose by 161 places from last year.
Bangkok was the most searched city this summer, followed by Paris and London.
HCMC welcomed 3.4 million international arrivals last year, around 30% of pre-pandemic levels in 2019. This year, the southern metropolis targets 5 million arrivals.
Hanoi received 1.5 million foreign tourists last year, just more than a quarter of 2019. The capital strives to attract three million foreign tourists this year.