Multibeam and marine sediment data were collected during three cruises with RV Sanna between 2018 and 2020 in Nuup Kangerlua fjords, Southwest Greenland. The goal of this project was to explore seafloor terrain and environment of the entire fjord system. (1) Multibeam bathymetry and backscatter data were aquired with hull-mounted Teledyne echo sounder SeaBat T50-ER (max. 1000 m) operated at 180 kHz. Positioning and movements of the vessel were obtained from the Applanix POS MV Surfmaster receiving data from an Integrated Motion Unit and two Trimble GNSS antennas. The accuracy of the observations is generally within 0.5 to 2 m horizontally and up to 0.03 degrees roll, pitch, and heading of the vessel. Multibeam data were SVP-corrected, tide-corrected, and cleaned using PDS software. Data were gridded at 10 x 10 m resolution for terrain analyses and at 50 x 50 m resolution for public dissemination, in accordance with Danish national hydrographic authorities and security-related restrictions on detailed seabed and depth information from national coastal waters. Gridded multibeam data were analyzed for seafloor landforms using hillshade, slope, and profile analyses which are also provided here as shapefiles. (2) Surface sediment images and samples were collected with drop camera and grab, respectively and these are summarized in Table S1.