Airborne electromagnetic (AEM) and magnetic survey data were collected during June 2012 along 556 line-kilometers over Iliamna Volcano, Alaska. These data were collected in support of alteration and volcano flank instability mapping as part of the U.S. Geological Survey (USGS) Volcano Hazards Program. Data were acquired by SkyTEM Survey ApS SkyTEM304 with the Soloy Helicopters Eurocopter Astar 350 B3 and Bell 407 dual-moment, time-domain helicopter-borne electromagnetic system together with a Geometrics G822A cesium vapor magnetometer with Kroum KMAG4 counter. The survey was flown at a nominal flight height of 30 meters (m) above terrain along block-style lines with a nominal spacing of 250 m. The survey was designed to cover the summit and flanks of Iliamna volcano and includes transit lines east of the volcano which provide additional information on nearby structures and glacial thickness and resistivity. There are data gaps near Iliamna’s summit due to poor flight visibility. Data acquisition, minimal processing, and initial inversions were conducted by SkyTEM Survey ApS and described in detail in the contractor’s report. The AEM depth of investigation varied with subsurface resistivity and averaged approximately 338 m. Raw digital data from production flights are provided and described in the data dictionary. Please see https://www.sciencebase.gov/catalog/item/5c8fb915e4b093882452b34a for the complete data package received from the contractor and the contractor’s report.