Three of them were handed prison terms while one was sentenced to juvenile custody by the court, Al-Ahram newspaper reported.
The charges against the four boys stem from a complaint filed by Muslim residents in Minya governorate, accusing a Coptic teacher, Gad Youssef Younan, and five of his students of insulting Islam.
Younan and his students were reportedly filmed in a video clip showing them mocking the Islamic State militant group while on a church outing in February 2015.
On January 30, Younan was sentenced to three years in prison for contempt of religion.
Coptic Christians make up roughly 10 percent of Egypt's population of 90 million and have long complained of discrimination and persecution.
Egyptian courts have recently convicted several individuals, both Muslim and Christian, of contempt of religion.