The trial is centred on the deadliest-ever crossing attempt between Morocco and Spanish enclaves.
Scores of migrants have been jailed in Morocco for attempting to scale a border wall to reach Spanish territory last month.
The court in Nador sentenced 33 people to 11 months in prison each over the deadly crossing attempt to the Spanish enclave of Melilla.
At least 23 people were killed in a "stampede" when hundreds of migrants tried to cross the North African border on June 24. An estimated 133 people successfully breached the frontier.
A spokesperson for the Spanish government’s office in Melilla said that about 2,000 people had attempted to cross, but many were stopped by Spanish Civil Guard police and Moroccan forces on either side of the border fence.
On Tuesday, the 33 migrants were found guilty of "disobedience," "armed gathering," "violence against public officials," and "illegal entry into Moroccan territory."
Authorities say the suspects were all from sub-Saharan Africa and most had travelled from Sudan and Chad. In addition to jail terms, they were all ordered to pay a fine of 4,000 dirhams (€379).
The verdict has been labelled "very harsh" by the Moroccan Association for Human Rights (AMDH) and other NGOs.
"We hope that the Court of Appeal will rectify this judgment," the AMDH said in a statement.
A second trial of 29 migrants over the mass crossing attempt has been adjourned until 27 July.
On Wednesday, the ADMH released a new report, blaming Rabat and Madrid for the migrant deaths at Melilla in June.