We present the world’s first time series acquired in the summit area of an active volcano with an absolute atom interferometry gravimeter. The device was installed ~2.5 km from the active craters of Mt. Etna volcano and produced a continuous high–quality gravity time series, despite the unfavorable environmental conditions at the installation site and the occurrence of phases of high volcanic tremor during the acquisition interval. Comparison with data from other gravimeters installed elsewhere on Mt. Etna highlights correlated anomalies, demonstrating that the quantum device measured gravity variations driven by bulk mass changes. The latter are reflective of volcanic processes, involving the dynamics of magma and exsolved gas in the upper part of Mt. Etna’s plumbing system. Our results confirm the operational possibilities of quantum gravimetry and open new horizons for the application of the gravity method in geophysics.