The court sentenced Sollecito to 25 years in jail for the murder and ordered his passport seized, judging him to be at risk of flight because of links abroad.
In a statement, the police said Sollecito had been found between the northern towns of Udine and Tarvisio, which is less than 10 kilometres from Italy's border with Austria.
The note said Sollecito had reached the area in the early afternoon of Thursday, hours before the guilty verdict was announced. Sollecito attended a morning hearing in Florence, but his lawyer said he would not attend the verdict due to stress.
"Raffaele Sollecito... was notified of the cautionary measures of the travel ban and the confiscation of his passport in the first hours of this morning," the note read.
Sollecito has not been taken into custody. According to the court's judgment, he can move freely within Italy, as the sentence is not yet definitive. He would begin his sentence if and when it was confirmed by Italy's highest court.
Knox is in her U.S. hometown of Seattle and would have to be extradited to serve a sentence. Her sentence of 28 years and six months must also be confirmed by Italy's high court to become definitive.