DeltaDTM is a global coastal Digital Terrain Model (DTM) available in the public domain, with a horizontal spatial resolution of 1 arcsecond (~30 m) and a vertical mean absolute error (MAE) of 0.45 m. It corrects CopernicusDEM using spaceborne lidar data from the ICESat-2 and GEDI missions. DeltaDTM improves upon previous methods by using classification rather than regression to correct elevation biases, resulting in more accurate terrain data. It is particularly useful for coastal flood impact modelling and other applications requiring high-accuracy elevation data. DeltaDTM is based on CopernicusDEM, ICESat-2, and GEDI data, and includes a classification process to identify terrain pixels, followed by interpolation to fill gaps. The resulting DTM has a mean absolute error of 0.45 m, with 91% of cells accurate within 1 m, compared to 0.72 m and 79% for the most accurate other high-resolution product. DeltaDTM is publicly available as a zipped archive and is licensed under CC BY 4.0. It is produced using Copernicus WorldDEM-30 data and is available for use in various applications, including coastal flood modelling. The dataset is also available on Google Earth Engine and includes mask tiles, a virtual raster table, and a geopackage with bounding boxes. DeltaDTM has been validated against local airborne lidar datasets and has shown high accuracy, particularly for coastal areas. It is currently the most accurate global coastal DTM available. The dataset is available for use in various applications, including coastal flood modelling, and is licensed under CC BY 4.0.DeltaDTM is a global coastal Digital Terrain Model (DTM) available in the public domain, with a horizontal spatial resolution of 1 arcsecond (~30 m) and a vertical mean absolute error (MAE) of 0.45 m. It corrects CopernicusDEM using spaceborne lidar data from the ICESat-2 and GEDI missions. DeltaDTM improves upon previous methods by using classification rather than regression to correct elevation biases, resulting in more accurate terrain data. It is particularly useful for coastal flood impact modelling and other applications requiring high-accuracy elevation data. DeltaDTM is based on CopernicusDEM, ICESat-2, and GEDI data, and includes a classification process to identify terrain pixels, followed by interpolation to fill gaps. The resulting DTM has a mean absolute error of 0.45 m, with 91% of cells accurate within 1 m, compared to 0.72 m and 79% for the most accurate other high-resolution product. DeltaDTM is publicly available as a zipped archive and is licensed under CC BY 4.0. It is produced using Copernicus WorldDEM-30 data and is available for use in various applications, including coastal flood modelling. The dataset is also available on Google Earth Engine and includes mask tiles, a virtual raster table, and a geopackage with bounding boxes. DeltaDTM has been validated against local airborne lidar datasets and has shown high accuracy, particularly for coastal areas. It is currently the most accurate global coastal DTM available. The dataset is available for use in various applications, including coastal flood modelling, and is licensed under CC BY 4.0.