We review the main characteristics of volcanic successions that commonly host important resources of gold, silver, nickel, copper, lead, zinc, and diamonds, and outline the connections between volcanic and ore-forming processes. Volcanic-hosted massive sulfide deposits form in submarine volcanic successions. They form at the same time as the volcanic facies accumulate, at or below the seafloor, and are by-products of the concentration of magmatic heat in areas of active submarine volcanism. Nickel sulfide deposits in komatiite successions comprise nickel sulfide minerals that precipitate directly from komatiite lava or intrusions. The sulfur is derived from an external source, such as assimilated sulfur-bearing sediment. Whether or not komatiite lavas or intrusions are mineralized, depends on their physical properties, especially the high temperature, high density, and low viscosity, all of which favor assimilation. Epithermal gold–silver deposits are formed by hydrothermal fluid circulation driven by heat from cooling intrusions and/or heat tapped by deeply penetrating faults. Because the fundamental mechanism for ore deposition is boiling of the hydrothermal fluid, these systems typically operate in subaerial settings. However, the mineralizing events can be significantly younger than the host rocks. Silicic calderas, silicic domes, andesitic cone volcanoes, and rhyolite maar volcanoes are all known to host epithermal deposits. Kimberlite pipes are the main source of diamonds worldwide. The diamonds in kimberlite magmas are xenocrysts and the magma simply serves to transport diamonds from their deep mantle source. Pipes are mainly filled by volcaniclastic facies generated by explosive fragmentation of kimberlite magma and wall rock. Kimberlite pipes probably connected to small pyroclastic cones at the surface but these landforms are rarely preserved.