You can easily find a taxi at the main exit of the airport. Apart from that, you can use online taxi services as listed below. You have to install the apps in advance.
♦ The airport taxi service operated by Airport and Aviation Services Limited, Sri Lanka – Click here for more information
♦ Other online taxi services
◊ PickMe Sri Lanka (https://pickme.lk/)
◊ Kangaroo Cabs Sri Lanka (http://www.2588588.com/)
◊ UBER