Due to subsidence of the runway and the proximity of the hills, the Government decided in 1947 to abandon Waterloo and make Lungi, a British Royal Air Force base, the airport for Freetown.

[3] The senior architect of the Public Works Department, Robin Halliday Macartney, supplied a draft plan for the terminal building,[4] which then became the responsibility of the airport engineer A. E. Pugh.

The new terminal building, finished in 1955, soon proved to be too small, and in 1960 it was decided to make Lungi a modern international airport.

The government of Sierra Leone undertook a general upgrade of the terminal in 2010, in order to meet the basic standards of current international airports.

From September 2014, almost all regional and intercontinental flights to Freetown were suspended as a result of the 2014 West Africa Ebola virus outbreak.

During this crisis, Brussels Airlines was the only carrier to maintain its regular operations to the airport; catering almost exclusively to NGO health workers.

Mamamah International Airport was expected to be operational by 2022, however the project was cancelled in October 2018 following a change of government.

The government Aviation Minister stated that they would refurbish Lungi instead and may build a bridge to better link the airport to Freetown.