The 113 kilo device was found on an industrial estate near Catania airport, forcing local authorities to evacuate all people within one kilometre of the site - an area which includes the airport.
Bomb disposal experts from the Italian Army were sent to the scene from Sicilian capital Palermo on Thursday morning. The airport was opened again at lunchtime after the bomb was destroyed in a controlled explosion.
Catania airport is Italy's 6th busiest airport with some seven million visitors each year and receives passengers from major European destinations including London, Berlin and Rome.
The closure of the airport caused disruption for travellers on Thursday morning and disrupted traffic on nearby roads and railway lines.
The airport said in a statement on its website that thirteen flights had been cancelled or diverted due to the bomb, with a further ten flights delayed until later in the day. A flight from Düsseldorf that had been due to land at 8:40am would now land more than seven hours late, the statement said.
Ryanair redirected their morning traffic to Comiso airport, 90 minutes drive away – wreaking havoc with confused holidaymakers, one of whom described it as an "omnishambles".
During the Second World War a large number of bombs were dropped on the island of Sicily as part of the allied invasion, otherwise known as Operation Husky. Operation Husky began on the 9th-10th July and ended August 17th. It was seen as a pivotal offensive during the war and opened the way for the invasion of Italy.
It is difficult to estimate how many unexploded WWII era bombs are still lying under Italian soil, but every year notable examples turn up in gardens and on beaches across the country as a deadly reminder of the war. In April, an unexploded WWII grenade was found near Bologna.
During the Second World War, Anglo - American forces dropped some 370,000 tones of bombs on Italy, causing 100,000 deaths. Sixty years ago, incidences of fuse failure were much more common and experts estimate they could have been as high as 30 percent. Last month in Cologne, large areas of the city were evacuated after a 1,000 kg bomb known as a “Block Smasher” was discovered in the city centre.
By late afternoon, the airport was reporting that flights were arriving and leaving as normal.