The U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center in Sioux Falls, SD developed a cloud validation dataset from 48 unique Landsat 8 Collection 1 images. These images were selected at random from the Landsat 8 archive from various locations around the world. While these validation images were subjectively designed by a single analyst, they provide useful information for quantifying the accuracy of clouds flagged by various cloud masking algorithms. Each mask is provided in GeoTIFF format, and includes all bands from the original Landsat 8 Level-1 Collection 1 data product (COG GeoTIFF), and its associated Level-1 metadata (MTL.txt file).