3 February – Treaty creating Benelux Economic Union signed, to come into force 1 November 1960, providing for free movement of workers, capital, services, and goods between Belgium, the Netherlands, and Luxembourg.
17 April – King Baudouin opens Expo 58, the first major World's Fair since the Second World War.: 184 John Carl Studder of El Paso, Texas, had queued for 48 hours to be the first visitor admitted.: 904
Demonstration of about 200,000 marches through Brussels to protest the Socialist government's education policy.: 904