The court in Dar El Beida on Thursday "sentenced 49 people to execution over [accused arsonist] Djamel Ben Ismail's murder and mutilation of his body", the APS news agency reported.
The court also handed 28 other defendants jail terms of two years to a decade without parole, APS said.
Onlookers had beaten 38-year-old Ismail to death after he turned himself in at a police station in the Tizi Ouzou region.
He had gone there upon hearing that he was suspected of arson, at the height of blazes, which killed at least 90 people nationwide.
Videos posted online at the time showed a crowd surrounding a police van and beating a man inside it, then dragging him out and setting him on fire, with some taking selfies.
The shocking images were widely shared and sparked outrage in Algeria.
Algeria's LADDH human rights group called for calm and for those responsible for the "despicable murder" to be brought to justice.
"These images constitute yet another trauma for the family and for the Algerian people, already shocked" by the fires, it said.
The victim's father, Noureddine Ben Ismail, was widely praised for calling for calm and "brotherhood" among Algerians despite his son's murder.
The fires were spurred by a blistering heatwave, but authorities also blamed arsonists and "criminals" for the outbreaks.
They also blamed the independence movement of the Berber-majority region of Kabylie that extends along the Mediterranean coast, east of Algiers.
The Movement for the Autonomy of Kabylie (MAK), which Algiers classifies as a "terrorist organization", rejected the accusations.
The court on Thursday also passed a life sentence against MAK president Farhat Mehenni, in absentia as he lives in exile in France.
Although much of Algeria's interior is desert, the north has more than four million hectares (10 million acres) of forest, which is hit every summer by fires.