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.

On 11 January, 32-year-old Whittingham will have been with the Bluebirds a decade, but his latest deal in the Welsh capital runs out in the summer.
It looks certain Whittingham will commit his future to the Bluebirds by signing a new contract.
"We'll talk about that before the FA Cup probably," said Warnock.
Cardiff face Fulham in the third round of the FA Cup on Sunday, 8 December, but before that, on Monday 2 January, the Bluebirds entertain Whittingham's former club, Aston Villa in the Championship.
Back in 2007, then-Cardiff boss Dave Jones, bought Whittingham from Villa for a fee of £350,000.
Since then, the dead-ball specialist has established himself as one of the most popular players ever to pull on a Cardiff shirt.
He has been named in the Championship Team of the Season three times and, in 2015, he was included in the Football League Team of the Decade.
Whittingham also finished joint-top scorer in the Championship in the 2009-10 campaign having found the net 20 times in the league for the Bluebirds.
During his time with Cardiff, Whittingham has turned down the chance of a move away from the Welsh club.
This season he is currently the club's joint-top scorer in the league having found the net five times so far.
But despite that, Warnock says he will not be rushed into a new contract to keep the midfielder.
"That's the least of my worries at the minute. I haven't sorted my own [contract] out yet, let alone Peter's," joked Warnock.
"Peter knows, I've said to him, 'you'll be here as long as me Peter' and he laughed and said, I know, that's what worries me.
"No, we've got a few days [before the Fulham game] then we've got no league points to worry about so we'll probably have a chat during that period."
A group of Italian scientists convicted of manslaughter for failing to predict a deadly earthquake have had the verdict quashed.
[NEXT_CONCEPT]
Cardiff City boss Neil Warnock has confirmed the club will start discussing a new contract for midfielder Peter Whittingham.