The attacks came as part of an intensified air campaign over Aleppo in recent weeks, despite an international outcry over the civilian deaths.
In the village of Hayyan, north of Aleppo city, barrel bombs killed two elderly men, a woman, and five children from a single family, the Syrian Observatory for Human Rights said.
North of the provincial capital, six civilians -- among them two children -- were killed when barrel bombs were dropped on the village of Deir Jamal.
On May 31, barrel bombs dropped on rebel-controlled areas throughout Aleppo province killed more than 80 people, one of the highest daily tolls since the beginning of 2015.
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UN's Syria peace envoy Staffan de Mistura called the civilian deaths "totally unacceptable".
Syria's conflict, which began in March 2011, has left more than 220,000 people dead and forced millions to flee.
Regime barrel bombs -- crude weapons made of containers packed with explosives -- have often struck schools, hospitals, and markets in Syria, despite condemnation by rights groups.
In Aleppo, Al-Nusra is facing an advance by its jihadist rival, the extremist Islamic State group.
On Sunday, IS wrested control of the village of Suran and advanced on Marea, a town on a key rebel supply route from Turkey.
The Britain-based Observatory says it has calculated that IS now controls half of all Syrian territory, and it is seeking to expand its control in Syria's north and centre.