Ahmaud Arbery, 25, was shot on 23 February 2020 in a confrontation with Travis and Gregory McMichael and their neighbour, William Bryan.
The defendants said they acted in self-defence during a citizen's arrest; prosecutors said race was a factor.
Gregory McMichael, 65, his son Travis, 35, and their neighbour William "Roddie" Bryan, 52, were arrested in May 2020.
Prosecutors alleged that Travis McMichael used a racial epithet and an expletive directed at Arbery as he lay on the ground. The men deny racism.
The men now face minimum sentences of life in prison.
A mainly white jury of 12 people deliberated for about 10 hours before returning their verdict at around midday on Wednesday.
The trio were found guilty of murder, aggravated assault, false imprisonment and criminal intent to commit a felony.
How did Ahmaud Arbery die?
Arbery was out jogging in the afternoon on the outskirts of the coastal city of Brunswick in Georgia.
The elder McMichael, a neighbourhood resident, told police he believed Arbery resembled the suspect in a series of burglaries in the suburban community of Satilla Shores.
Police have said no reports were filed regarding these alleged break-ins, and no stolen property was found in Arbery's possession.
The McMichaels armed themselves with a pistol and a shotgun and pursued Arbery, who was unarmed, in a pickup truck through the neighbourhood. Bryan later joined the pursuit.