The first PM of Sierra Leone was Sir Milton Margai.
Sir Milton Augustus Strieby Margai , PC ( 7 December 1895 -- 28 April 1964 ) was a Sierra Leonean politician and the first prime minister of Sierra Leone . Sierra Leone . Sierra Leone became an independent Nation on 27 April 1961 from Britain , led by Sir Milton Margai , who was elected by landslide as the first prime minister of the new nation under parliamentary government .