There are international flights on Vietnam Airlines and Royal Khmer Airlines to Siem Reap.

By Vietnam Airlines

From		To		Transit	Flight (VN)
City	Time	City	Time	None	823
HCMC	15:40	Siem Reap	16:40
HCMC	18:35	Siem Reap	19:35	None	849

* Flight time and schedules may change, please check on actual date for the update.

By Royal Khmer Airlines

From		To		Transit	Flight
City	Time	City	Time	None	RK 678
HCMC	14:50	Siem Reap	16:00

* Flight time and schedules may change, please check on actual date for the update.

See also:

Return flight

Flights from Siem Reap to Ho Chi Minh City

Other flights from Ho Chi Minh City to Cambodia

Flights from Ho Chi Minh City to Phnom Penh

International flights from Hanoi

Flights from Hanoi city to Phnom Penh.
Flights from Hanoi to Siem Reap