The seven men had been given six-year jail sentences after an earthquake devastated the medieval town of L'Aquila in 2009, killing 309 people.
The verdict triggered alarm, with some saying that science itself had been put on trial.
On Monday an appeals court cleared the group of the manslaughter charges.
Judge Fabrizia Ida Francabandera ruled that there was no case to answer.
"The credibility of Italy's entire scientific community has been restored," said Stefano Gresta, the president of the National Institute of Geophysics and Volcanology.
The seven men - all leading scientists or disaster experts - had been members of a committee convened in L'Aquila in March 2009 following a series of tremors in the region.
Days after they met, a 6.3 magnitude quake struck the town in the middle of the night.
Many of L'Aquila's medieval buildings were destroyed, and some locals blamed the disaster committee for not providing adequate advice.
Prosecutors in the subsequent trial said the experts had offered falsely reassuring information to residents.
According to Reuters, they noted that one committee member had said there was "no danger" from the tremors.
Following the guilty verdicts, more than 5,000 scientists signed an open letter to Italian President Giorgio Napolitano in support of the experts.
Many argued that the convictions represented a fundamental misunderstanding of earthquake science.
Monday's decision to overturn the verdicts came after a month-long appeal process.
The prosecution can still seek to have the original verdicts reinstated via a higher court.
A group of Italian scientists convicted of manslaughter for failing to predict a deadly earthquake have had the verdict quashed.