The Geochemical and geologic database for Mesoproterozoic igneous rocks and iron oxide-apatite-rare earth element (IOA-REE) and iron oxide-copper-cobalt-gold (IOCG) deposits of Southeast Missouri, 2016-2017 'Geochemical Database for Iron Oxide-Copper-Cobalt-Gold-Rare Earth Element Deposits of Southeast Missouri, 2016-2017' (MO_ROCK_IOCG_REE_GX2017) contains new geochemical data compilations for samples from Mesoproterozoic igneous rocks and iron oxide deposits of the Precambrian basement of southeast Missouri. Each sample has one "best value" determination for each analyzed species, greatly improving speed and efficiency of use. MO_ROCK_IOCG_REE_GX2017 was created and designed to compile whole-rock and trace element data from southeast Missouri in order to facilitate petrologic studies, mineral resource assessments, the definition and statistics of geochemical baseline values, and areas of anomalous concentrations of metals. This relational database serves as a data archive in support of present and future geologic and geochemical studies of IOA-REE and IOCG type deposits, and contains data tables in two different formats describing historical and new quantitative and qualitative geochemical analyses. It is designed to be used with the earlier ScienceBase data release of Day and others, 2017. The analytical results were determined by 19 laboratory analytical methods on 215 rock samples collected during two phases from outcrop and drill core sites from throughout the entire St. Francois Mountains terrane made by the U.S. Geological Survey (USGS). From 2013 to 2017 the USGS collected and analyzed 119 samples, and 96 samples collected and analyzed from 1989 to 1994 were reanalyzed in 2017 using modern analytical methods of higher precision. The data presents the most precise analytical approach to report the best value for each element. The original data from the 96 samples are currently maintained in the USGS National Geochemical Database (NGDB), and data from the 119 samples plus the reanalysis data of the 96 samples will soon be added. The data of the IOCG-REE_GX were checked for accuracy regarding sample location, sample media type, and analytical methods used. Reference: >Day, W.C. Day, Granitto, Matthew, Ayuso, R.A., and Slack, J.F., 2017, Geochemical Database for Iron Oxide-Copper-Cobalt-Gold-Rare Earth Element Deposits of Southeast Missouri: U.S. Geological Survey ScienceBase, v. 1.1, http://dx.doi.org/10.5066/F7P26W67.