Satellite radar estimates of sea-ice thickness may be derived from radar freeboard or ice freeboard. Radar freeboard is based on the reflection of radar signals from the top of the sea ice or an icy layer within the overlying snow. Ice freeboard is derived from radar freeboard corrected for delays in propagation through snow. Studies in the Arctic have allowed in-depth comparisons of these two parameters, but there are no such studies for the Southern Ocean. Greater precipitation in the Southern Ocean, along with flooding and refreezing, is known to create multiple ice layers within snow. These layers (which are rare in the Arctic) make the relationship between radar and ice freeboard more complex. We compare twenty years of satellite-based radar and ice freeboards retrieved from three distinct products. These satellite-derived freeboards are evaluated against independent in situ upward-looking sonar observations in the Weddell Sea. In the Southern Ocean, we observe that different satellite-derived radar and ice freeboards display consistent patterns in their spatial and seasonal distributions, though the magnitude of freeboard varies between product and freeboard type. Freeboards are highest in the western Weddell Sea, Ross Sea, coastal East Antarctic and Amundsen-Bellingshausen seas, consistent with previous observations.