The Tribhuvan International Airport of Kathmandu is the only international airport of Nepal.
The airport has two terminals, a small one for domestic flights and a large international terminal. The international terminal is used by over thirty airlines for connections to numerous cities in Asia and the Middle East.
The Tribhuvan International Airport is located in the Kathmandu Valley, about 6 km east of central Kathmandu.
The Sajha Yataya company provides a shuttle bus into the city, it departs in front of the international terminal (NPR 30). Local buses do not stop at the airport but you can walk to the airport gate and hop onto one. Local buses are crowded and slow but cost only NPR 10.
If you come on a trakking or touring package tour the airport transfer to your hotel is most likely included. Look for someone holding a sign with your name outside the arrivals area.
Pre-paid taxis at the official taxi booth to the popular tourist area of Thamel will cost about NPR 800. You can also try to get a regular taxi outside but you would need to negotiate; then the fare should be around NPR 500. If you are up for a walk you can walk outside the airport, across the parking lot where there are also taxis who do not need to pay the airport entrance fee. Here, also after heavy negotiations, you may get a taxi for NPR 300.
All prices quoted here were found in July 2017