To aid in geologic studies of sediment transport and environmental change in coastal marsh, 1-centimeter (cm) foraminiferal subsamples were taken from seven sediment push cores collected in the Grand Bay National Estuarine Research Reserve (GNDNERR), Mississippi, in October 2016. The push cores were collected along two, shore-perpendicular transects at 5, 15, 25, and 50 meters (m) from the shoreline, on opposite sides of Middle Bay during U.S. Geological Survey (USGS) Field Activities Number (FAN) 2016-358-FA, also known as alternate FAN 16CCT07. Foraminiferal subsamples were processed and analyzed at the USGS St. Petersburg Coastal and Marine Science Center (SPCMSC). Sediment characteristics, loss-on-ignition (LOI), and site location information for the core sites can be found in Marot and others (2019; https://doi.org/10.5066/P9FO8R3Y). Downloadable data are available as Excel spreadsheets (.xlsx), comma-separated values text files (.csv), and Federal Geographic Data Committee (FGDC) metadata (.txt and .xml).