Sixty five years after the unconditional surrender of Nazi Germany, the city in Brittany was closed as engineers worked to defuse a 550lb RAF device.
It was one of thousands dropped on northern France in 1944 as Allied troops prepared to invade.
Some 10,000 people living in Rennes were involved in the evacuation as the centre of the city resembled a ghost town.
“I remember the bombing raids during the war when hundreds were killed,” said Maurice Leclerc, an 81-year-old pensioner who was among the evacuees.
“The fact that the bombs are still disrupting our lives all these years on is truly incredible.”