Thirty-eight Muslims had faced the death penalty for their role in the clashes, which swept the village of Al-Kosheh, about 275 miles south of Cairo, just over a year ago.
Twenty Christians and one Muslim died after a dispute between a Muslim and Christian over a piece of cloth degenerated into several days of killings and looting.
Security forces ringed the court as the judge delivered his verdict in what has been an extremely sensitive case. In the end, however, the harshest sentence was 10 years in jail for just one man, convicted of accidental homicide and illegal possession of a weapon.
Many had expected lenient verdicts on the grounds that the police had not prepared a proper case against the suspects.
But the ruling will leave many in the Christian community angry. Although 20 Christians died, no one has been found guilty of their murder. A local priest told the BBC that justice had not been done. He said security forces who had stood by while Christians were being killed had then protected the killers from punishment.