The network says the exclusive interview will air on a prime-time special on April 30. It also will be featured on other ABC News programming.
Knox was an American student studying in Italy when, in 2007, she became the center of a murder case that seized the world's attention. She was convicted in 2009. But after an appeal, she was acquitted and released in October 2011.
The interview is timed to the publication of Knox's book, "Waiting to Be Heard."