The South Korean girl band arrived in the capital Friday night for their two concerts at the My Dinh National Stadium during the weekend.
On Friday night Hoang Minh, a Hanoian, planned to book a ticket from HCMC to Hanoi and was shocked to see only business class was available.
"The one-way ticket was higher than the round-trip fares during Tet," he said, referring to the Lunar New Year holiday when air tickets are usually most expensive and difficult to get.
On the Vietnam Airlines website there are only three available flights by 6 p.m. for the HCMC-Hanoi route on Saturday with economy fares being sold out while business class tickets were VND8.8 million.
Vietjet Air, Bamboo Airways and Vietravel Airlines said they were full up until 6 p.m. Saturday.
Nguyen Tien Dat, general director of Hanoi-based AZA Travel, said the jump in fares hike was "definitely triggered by the travel rush for the Blackpink concerts" as K-pop fans sought to watch the first ever show in Vietnam by the group.
The show starts around 7:30 p.m., and so those who cannot fly in to Hanoi before 6 p.m. will find it difficult to be at the venue in time.
The hospitality industry is also expected to benefit.
Many hotels in the My Dinh area are fully booked during the weekend.
Marina Hotel in Me Tri District, not far from the My Dinh National Stadium, has 40 rooms and all are booked.
Two weeks ago four-star hotel Reyna had reported there were no rooms available for July 29-30.
Phuong Anh, a salesperson at the Memory Premier Hotel & Spa in Hoan Kiem District, said all three hotels in the chain were almost full.