The Liquiñe-Ofqui fault system (LOFS) in south-central Chile provides a natural laboratory to assess the interplay between magma/hydrothermal fluid flow and crustal deformation. Understanding these processes is of paramount importance for geothermal energy exploration and seismic hazard assessment. We deployed a dense seismic network (Sielfeld et al., 2019) at the northern termination of the LOFS in south-central Chile (~38°S) between 2014 March and 2015 June. The main aim was to better understand the significance and implications of seismic activity in relation to geological information such as the complex fault-fracture network, volcanoes, and the stress field estimated from geological data. As a result, the network was designed to monitor the northern segment of the LOFS on a more regional scale rather than concentration on the activity of one volcano. The network covered a ~200‐km‐long section of the Southern Volcanic Zone, including several Holocene stratovolcanoes (Callaqui, Copahue, Caviahue Caldera, Tolhuaca, Lonquimay, Llaima, Sierra Nevada, Sollipulli, Villarrica, Quetrupillán, Lanín (La), and Mocho‐Choshuenco). Waveform data are open and available under network code 3H from the GEOFON data centre under license CC BY 4.0.