The pair stood accused of committing manslaughter and sexual violence against the exchange student. They were convicted in 2009, but acquitted two years later.
The acquittal was overturned and a subsequent appeal ruling in January 2014 saw Mr Sollecito again found guilty and sentenced to 25 years in jail.
But in March 2015, Italy's highest court overturned that decision - the final ruling.
Last year, the police found Mr Sollecito near the Italian border and confiscated his passport. He remained free while awaiting the Supreme Court's decision.
Amanda Knox, residing in the US, also had her conviction overturned. She had been sentenced to 28 years and six months.
From the start of the highly publicised case, Ms Knox - who lived with Ms Kercher - became the primary focus of media attention, leaving Mr Sollecito a somewhat shadowy figure in the background.
"Even though Amanda and I shared the same unjust fate, the case was always about her," the Italian wrote in his 2012 memoir Honor Bound: My Journey to Hell and Back with Amanda Knox.
"I vanished so far from public view that I thought of myselfâ€¦ as Mr Nobody."
The book was released after the former couple's acquittal and thrust Sollecito into the limelight for the first time.
In it, he describes how he refused to cave in to pressure from his family to testify against his then girlfriend. He said his main aim had been to "save" Amanda from finishing her days in prison.
"If I had changed my testimony, Amanda would have remained behind bars for the rest of her life, not just the 26 years to which she was originally sentenced. And that was something my conscience could never permit."
The son of a successful urologist, Raffaele Sollecito was born on 26 March 1984 in the southern Italian city of Giovinazzo.
He was on the verge of completing a computer science degree at Perugia University when he met Amanda Knox, an exchange student from Seattle, at a classical music concert in October 2007. Their encounter took place just days before Ms Kercher's death.
"It was a really nice relationship," he said in an interview.
"In that period she was much more at my apartment than in her one. It was an intense story, it was the start. It was crazy."
It was the same flat - bought for Mr Sollecito by his parents - where Ms Knox claimed she spent the night when Ms Kercher was murdered. This contradicted reports of her initial police statement, which originally placed her at the scene of the crime.
Mr Sollecito's defence was that on the night of the murder he was at home surfing the internet - although police said his computer records did not support the alibi.
He has also admitted smoking marijuana at the time. Both Mr Sollecito and Ms Knox admitted a fondness for the drug - which they blamed for their inability to recall their movements on the night Ms Kercher died.
In a letter to an Italian magazine he wrote: "One morning you return to her house and find a big mess. The problems begin: the police arrive, break down the locked door to a bedroom and discover the lifeless body of one of her (Amanda's) friends. From then on they suspect everyone and everything."
The pair's defence was not helped by CCTV evidence leaked to the Italian press, reportedly showing them buying erotic lingerie and discussing "wild sex" barely 24 hours after Ms Kercher's death.
Mr Sollecito's DNA was found on Ms Kercher's bra clasp.
In the end, the jury sided with the prosecution and found them both guilty. Mr Sollecito's impassive face provided a stark contrast to Ms Knox who broke down in tears in the courtroom.
Sent to separate prisons, Mr Sollecito later said of Ms Knox that her image continued to conjure up "the image of a nightmare".
In letters from his cell, he wrote: "The Amanda I know... lives a carefree life. Her only thought is the pursuit of pleasure."
"But," he added, "even the thought that she could be a killer is impossible for me."
The pair spent four years in jail before their conviction was overturned in October 2011 on the grounds that DNA evidence was flawed.
Appearing on US talk shows, Mr Sollecito revealed that he still shared "a really strong bond" with Ms Knox, whom he had visited in Seattle a few months after their release.
"After she hugged me, I realised that Amanda is the Amanda that I dated for that week. She's not the Amanda that was the ghost Amanda during those four years," he said in an interview with ABC.
When asked if they were still dating, he replied: "No, no - she's with another boyfriend and I am going on with my life. We are really good friends now but no, no there is nothing between us now."
In July last year he distanced his legal case from hers saying that Ms Knox was not present in his house at the time of Ms Kercher's murder as she has claimed.
The BBC's Ruth Alexander met Mr Sollecito in Perugia in August last year and said although he sounded exasperated at times over the accusations made against him, he only rebuffed questions about Amanda Knox.
"I really don't want to make any comment or be a defence team for her," he said.
Raffaele Sollecito was 23 and about to finish his degree when he was arrested along with then-girlfriend Amanda Knox for the 2007 murder of British student Meredith Kercher in Italy.