Antarctic geothermal heat flow (GHF) affects the ice sheet temperature, determining how it slides and internally deforms, as well as the rheological behaviour of the lithosphere. However, GHF remains poorly constrained, with few borehole-derived estimates, and there are large discrepancies in currently available glaciological and geophysical estimates. This SCAR White Paper details current methods, discusses their challenges and limitations, and recommends key future directions in GHF research. We highlight the timely need for a more multidisciplinary and internationally-coordinated approach to tackle this complex problem.