But her Italian legal drama is not quite over.
On Monday, Italy's highest court will conduct the final step in Knox's legal process, announcing whether it agrees with the appeals court's decision to free her, ABC News reports.
The prosecution in the case has appealed Knox's acquittal in a 100-page report, which questions apparent contradictions in the ruling.
Knox won't be physically present at the hearing, but she will be following what happens at her home in Seattle.
Knox was an American student studying in Perugia, Italy, in 2007 when she became the center of a murder case that seized the world's attention after her British roommate, Meredith Kercher, was found stabbed to death.
She and her then-boyfriend, Raffaele Sollecito, were convicted in 2009 of Kercher's murder, which allegedly happened during a drug-fueled sex assault.
But after an appeal, Knox and Sollecito were acquitted and released in October 2011. The fatal blow to the prosecution's case was a court-ordered DNA review that discredited crucial genetic evidence used to convict Knox and Sollecito in 2009.
The worst outcome for Knox from Monday's high court hearing would be a re-trial - and another agonizing wait for it all to end.
In the meantime, Knox's defense has appealed her slander conviction - a result of her falsely accusing her former boss, Patrick Lumumba, as her roommate's killer.
In 2009, Knox testifed that she suggested Lumumba after she was hit in the head, yelled at and confused during nearly 50 hours of interrogation by Italian police.
"We believe what Amanda has told us because she is extremely honest," says her father, Curt Knox.
Amanda Knox has already served the three-year sentence for slander during her four years in prison.
In Seattle, Knox is back in class at the University of Washington. She spends free time with her boyfriend, James Terrano, her three sisters or playing the guitar.
She has dedicated the past year to writing a book, "Waiting to be Heard," about her trial and four years in Italian prison that is scheduled for release next month.