Volatiles contribute to magma ascent through the sub-volcanic plumbing system. Here, we investigate melt inclusion compositions in terms of major and trace elements, as well as volatiles (H 2 O, CO 2 , SO 2 , F, Cl, Br, S) for Quaternary Plinian and dome-forming dacite and andesite eruptions in the central and the northern part of Dominica (Lesser Antilles arc). Melt inclusions, hosted in orthopyroxene, clinopyroxene and plagioclase are consistently rhyolitic. Post-entrapment crystallisation effects are limited, and negligible in orthopyroxene-hosted inclusions. Melt inclusions are among the most water-rich yet recorded (≤ 8 wt% H 2 O). CO 2 contents are generally low (< 650 ppm), although in general the highest pressure melt inclusion contain the highest CO 2. Some low-pressure (< 3 kbars) inclusions have elevated CO 2 (up to 1100-1150 ppm), suggestive of fluxing of shallow magmas with CO 2-rich fluids. CO 2-trace element systematics indicate that melts were volatile-saturated at the time of entrapment and can be used for volatile-saturation barometry. The calculated pressure range (0.8-7.5 kbars) indicates that magmas originate from a vertically-extensive (3-27 km depth) storage zone within the crust that may extend to the sub-Dominica Moho (28 km). The vertically-extensive crustal system is consistent with mush models for sub-volcanic arc crust wherein mantle-derived mafic magmas undergo differentiation over a range of crustal depths. The other volatile range of composition for melt inclusions from the central part is F (75-557 ppm), Cl (1525-3137 ppm), Br (6.1-15.4 ppm) and SO 2 (< 140 ppm), and for the northern part it's F (92-798 ppm), Cl (1506-4428 ppm), Br (not determined) and SO 2 (< 569; one value at 1015 ppm). All MIs, regardless of provenance, describe the same Cl/F correlation (8.3 ± 2.7), indicating that the magma source at depth is similar. The high H 2 O content of Dominica magmas has implications for hazard assessment.