Multibeam-bathymetry data provides a high resolution 3D rendering of the seafloor that, when collected offshore large marine-terminating glaciers, inform us about potential warm water pathways towards their grounding lines, as well as about the terrain that ice has moved over and shaped in the past. Now available is a new compilation of multibeam-bathymetric data for the inner Amundsen Sea continental shelf beyond Thwaites and Pine Island glaciers. The primary dataset was collected in 2019 by the THOR team during the first cruise of the International Thwaites Glacier Collaboration (ITGC). Additional data were acquired by other UK, German, USA and Korean scientific cruises to the area between 1999 and 2019. The region includes Pine Island Bay, marine areas offshore the Thwaites Ice Shelf to the Crosson Ice Shelf, and covers an area of 74,750 km². More than 2000 km² of new data were acquired immediately offshore the western Thwaites Ice Shelf in an area previously made inaccessible by persistent sea-ice and icebergs. Data are available at two resolutions (50m and 500 m) in ESRI ascii interchange and GMT-compatible netCDF 4byte float formats. Note that these grids have not been merged with regional bathymetric grids and, therefore, cells are only populated where multibeam data exist.