This dataset comprises broadband seismic data from the Askja Caldera, Iceland, which consists of ~12 months of continuous recording from August 2023-August 2024. A total of 23 Guralp 6TD and Certimus seismometers were deployed in and around the ~8km diameter caldera, with sampling rates set to 100sps. Each seismometer was buried ~30cm below the surface, and attached to a power supply consisting of 3 100Amp-hour batteries and 100 W solar panels mounted on a wooden frame. The batteries were placed in a box that sat on the supports of the solar panel frame to act as ballast, and wrapped in a plastic sheet. A Gps unit was mounted on the solar panel frame. Access to most stations is by foot, and installation was undertaken either by carrying the equipment on foot or by helicopter. The dataset provided is in standard miniseed format, and has an accompanying dataless file for each instrument type in xml format. The miniseed data is archived in day files under the directories "2023" and "2024", while the xml file is located in the directory "dataless". The data is of good quality, with both local earthquakes and teleseisms easily detected. The data were collected for the purposes of tracking microseismic activity associated with the recent reinflation event at Aska, and to help facilitate seismic imaging beneath the caldera using both body and surface wave tomography. The data may be of use to other scientists with an interest in earthquake seismology, imaging, and characterisation of geothermal areas near active volcanoes. The data were collected by the University of Iceland and University of Cambridge, both of who are responsible for interpretation of the data. The archive is complete as it currently stands. The data were converted into miniseed using a standard format that is consistent with archives stored at the IRIS DMC.