The slander conviction was based on statements Knox made to police in November 2007 when she was being questioned about the slaying of her British roommate, Meredith Kercher, in the house they shared in Perugia.
Knox says she was coerced into making false statements blaming the slaying on bar owner Patrick Lumumba.
"The interrogation took place in a language I barely spoke, without a lawyer present, and without the police informing me that I was a suspect in Meredith's murder, which was a violation of my human rights," Knox said in a statement released Monday as the appeal was filed.
Knox was convicted of slander at her first trial in December 2009. That conviction was upheld during the appeal that resulted in her 2011 murder acquittal.
Knox has returned to Seattle, where she is a student at the University of Washington. She is not attending the third trial being held in an appeals court in Florence.
The European Court for Human Rights is an international court in Strasbourg, France, that oversees the European Convention on Human Rights.