From Vietnam, you can get to Cambodia by both flight and border crossing. There are 3 international airports in Hanoi, Ho Chi Minh, and Da Nang that serve the flight to Cambodia. If you choose to go to Cambodia by overland, there are 7 border crossings for you to do so.
Let's check the below maps to see the locations of the airports and border checkpoints that help you get to Cambodia from Vietnam
From Vietnam to Siem Reap
As a tourist hub of Cambodia, there are plenty of flight to Siem Reap from Vietnam every day.
From Hanoi, there are 3 direct flights per day operated by Vietnam Airlines and VietJet Air. The flight takes about 2 hours with the price ranges from $76 to $125/ticket. You can either have the option to transit in Luang Prabang with Vietnam Airlines. The flight is still convenient enough as you do not need to change the flight during the transition.
From Ho Chi Minh city, there are more than 4 departures per day operated by Vietnam Airlines and Cambodia Angkor Air. The flight will take about 1 hour 30 minutes and costs about $100-180/ticket.
The option to flight from Danang is quite limited, there is only 1 departure per day operated by Cambodia Angkor Air. The flight takes more than 2 hours and costs about $120/ticket.
From other tourist hubs such as Halong, Nha Trang, or Phu Quoc, you need to take find the connection flight via Hanoi, Ho Chi Minh city, or Da Nang.
From Vietnam to Phnom Penh
Though the capital of Cambodia, there is less flight from Vietnam to Phnom Penh than to Siem Reap.
From Ho Chi Minh city, there are at least 5 direct flights per day to Phnom Penh operated by Cambodia Angkor Air, Vietnam Airlines, or Qatar Airways. The flight takes about 1 hour and costs about $72 to $170/ticket.
From Hanoi, there is no direct flight yet. The best way is to take the transit flight via Vientiane or Ho Chi Minh city. This option is still convenient enough as you do not need to get out of the plane during the transition.
The option via Vientiane costs higher (about $230-250/ticket) but it takes less time (about 3 hours and 20 minutes including the transiting time)
The option via Ho Chi Minh takes longer travel time (about 5 hours in total) but it costs less ($150/ticket)
From other cities, you need to go to Ho Chi Minh or Hanoi to take the flight to Phnom Penh
From Vietnam to Sihanoukville
There is only the direct flight from Ho Chi Minh city to Sihanoukville with 1 departure per day operated by Cambodia Angkor Air. The flight takes about 1 hour and costs about $90-130/ticket
From other cities including Hanoi, you need to take the transit flight via Ho Chi Minh.
1. O Yadao / Le Thanh crossing (Google Maps)
The crossing here is very remote, and hardly used by foreign tourists. Connecting Ban Lung in northern Cambodia with Pleiku in Vietnam and takes around six hours to travel. There are transports to the border on both sides, and the average cost for the whole trip is around US$ 25.
2. Snoul / Hoa Lu (Google Maps)
This border gate connects the remote northeast of Cambodia with the southwest part of Vietnam in Binh Phuoc Province. It is popular for the bus from Pakse (southern Laos) running to Ho Chi Minh city via Cambodia.
It is also the shortest route to the light of Ho Chi Minh city after the wildlife exploration in Cambodia.
3. Trapang Thlong / Xa Mat (Google Maps)
This is one of the least visited border gate by tourists between the two countries. This border crossing is more popular among the local passengers from the two countries, especially for Vietnamese gamblers go to Cambodia and try their luck (most of them cannot make it)
4. Bavet / Moc Bai (Google Maps)
This is the oldest and still the most popular crossing point from Cambodia to Vietnam that is open to foreign tourists. There are regular buses that run daily from Phnom Penh to Ho Chi Minh City, and they are fast and cheap. The average crossing time is normally around six hours, including the stopping time at the border for passport checks.
5. Phnom Den / Tinh Bien (Google Maps)
Lying around halfway between Ha Tien and Chau Doc, this border crossing is one that is rarely used by foreign tourists, although it does allow foreign transit. It is a couple of hours drive from the towns either side of the border to the crossing point, which makes it hard to get to by independent travelers.
6. Prek Chak / Ha Tien (Google Maps)
Set on the coastal border point between Cambodia and Vietnam, this crossing is now open to foreign tourists, and transport from Ha Tien to the border is frequent and cheap. On the Vietnam side, there are moto taxis waiting to transport passengers to the nearest town of Kep, which cost around US$ 7.
7. Kaam Samnor / Ving Xuong (Google Maps)
The seventh land border crossing is the river crossing that links Phnom Penh with the town of Chau Doc in Vietnam, using the Mekong River. There are regular ferry services that ply the route across the border, or if you are feeling adventurous, you can get a speedboat crossing. The speedboat crossing takes around four hours, while the regular ferry, while fast, still take 6-7 hours. When you get to the border point on the river, the boats pull to the shore, and a “fixer” will gather up all your documents to process the paperwork for you. You can accompany them if you wish, although it is not required.