The executions were reported by Indonesian media cited by Reuters.
The eight included nationals of Indonesia, Australia, Brazil, Nigeria and France.
The death sentences were carried out despite condemnation from the UN, and have strained relations with its Australian neighbour.
The prisoners were given the choice to stand, kneel or sit before the firing squad, and to be blindfolded. Their hands and feet were tied.
Twelve marksmen were assigned to each prisoner, but only three used live ammunition so the executioner would not be identified.
It is believed to be the biggest mass execution in this country for decades.
Two of those killed were Australians Andrew Chan, 31, and Myuran Sukumaran, 34, who were arrested in 2005 for attempting to smuggle 18.5 pounds of heroin out of Indonesia. Both had admitted their guilt.
Mary Jane Veloso, a 30-year-old maid from the Philippines, was spared execution, according to reports. She said she had been asked to take a case to Indonesia before starting a new job. Police found six pounds of heroin in the case when they searched it at Java airport.
Family members, lawyers and embassy officials travelled to Nusakambangan prison island ahead of the executions.