Measurements of volcanic degassing play a key role in monitoring and hazard mitigation at active volcanoes, and underpin assessments of volcanic impacts on the environment, climate and health. Satellite remote sensing has provided critical observations of volcanic sulfur dioxide (SO2) emissions during major eruptions since 1978. Since the 1990s, advances in instrumentation and trace gas retrieval techniques have increased the sensitivity of ultraviolet (UV) satellite SO2 measurements by several orders of magnitude. This now permits global monitoring of SO2 emitted both during and between volcanic eruptions, increasing the viability of satellite data as a volcano monitoring tool. In this paper, we review recent developments in satellite instrumentation, SO2 retrieval algorithms and data analysis techniques used to quantify global volcanic SO2 emissions. The launch of a geostationary UV satellite constellation in the coming decade will further advance space-borne UV volcano monitoring.