The Efficiency Decoration (South Africa), post-nominal letters ED, was instituted in 1930 for award to efficient and thoroughly capable part-time officers in the Citizen Force of the Union of South Africa after twenty years of service. The decoration superseded the Colonial Auxiliary Forces Officers' Decoration.

Field Marshal Jan Christian Smuts, was a South African statesman, military leader and philosopher. In addition to holding various military and cabinet posts, he served as prime minister of the Union of South Africa from 1919 to 1924 and 1939 to 1948.