The airport is located in the Buhangin district, about 15 - 30 minutes away from downtown Davao, depending on the mode of public transportation you'll choose.
You can reach the airport by taxi or jeepney.
Taxi
This is the more convenient option. When you have heavy baggage or don't have much time or simply never minds the cost, then hail a cab. Taxis can enter the airport unlike jeepneys so the only hassle you might encounter is the traffic. The cost will be around Php150 to and from downtown.
Jeepney
Many jeepneys are passing the airport day and night. If you have a tight budget, then this one is for you since you get to pay only around Php10-15 to and from downtown. The fare is Php8 for the first five kilometers and an additional Php1 for every kilometer after that. However, expect that you will be riding for about 30 minutes to 1 hour depending on the traffic.
Going to the airport:
a. When you are in downtown, you can find in Bajada (J.P. Laurel Ave.) most jeepneys that pass through the airport. The good spots are in Gaisano Mall, Victoria Plaza, and Abreeza Mall since there are persons who help jeepney drivers to get passengers. You can easily spot them as they are shouting destinations and calling passengers. In return they get a tip from the driver. Simply tell them that you are going to the airport and they will lead you to the right jeepney. If you cannot spot one, then check the routes written on the side, front, and window shield of the jeepneys. Look for "Landmark", "Bunawan-Roxas", "Panacan-Illustre", "Tibungco-Roxas" and ask the driver if it will pass the airport to be sure. Upon riding the jeep, pay the fare right away and tell the driver to drop you at the airport.
b. The jeepney driver will drop you at the road near the airport entrance gate. You have to walk for about 5 minutes to the main airport building.
From the airport to the city:
a. Upon getting out of the airport building, turn right and walk for about 5 minutes to the main road. Just follow the trail of the cars getting out. Recently, during my last visit at the airport, there's a multicab (small jeepney) just outside the airport building, right after the taxis, that takes you outside, to the main road. You may take that if you want, the fare is Php7.
b. If you're heading to downtown or Bajada area, cross to the other side of the road and look for jeepneys with Bajada or G-mall on signboards.
If you are unsure, don't be afraid to ask questions. Davaoeños will help you with the right directions.