Lithologic and thickness data of the successive Paleocene and Eocene stratigraphic units in panhandle and peninsular Florida were obtained by investigating cuttings, cores, and electric logs of a total of 164 wells selected for this study. These data were employed for constructing isopachs-lithofacies maps, structure maps and lithologic cross sections. These maps and cross sections together with the paleontologic information make possible more reliable interpretations of sedimentary petrogenesis and of the regional tectonics of the Paleocene and Eocene time in Florida. Two distinct sedimentary facies, clastic (panhandle Florida) and nonclastic (peninsular Florida), have been recognized and differentiated on a series of isopach-lithofacies maps of the successive stratigraphic units of the Paleocene and Eocene Series in the area studied. These two sedimentary facies were separated by the Suwannee Channel, which acted as a natural barrier, both sedimentological and faunal, and occupied a narrow belt along southern Georgia and northern Florida with a northeast-southwest trend during the time from late Upper Cretaceous to Upper Eocene. The barrier nature of the Suwannee Channel gradually became less effective and finally disappeared near the end of Eocene time. On the basis of lithologic and paleontologic data together with the ecologic an environmental conditions inferred in this study, the following interpretations concerned with the regional sedimentation were made. In peninsular Florida, nonclastic sediments, carbonates and evaporates, were formed on a stable carbonate bank or shelf in warm, shallow-water, and open marine environment which could be comparable to those existing today in the Great Bahamas, Florid Bay and keys, and Campeche Banks. In panhandle Florida, clastic sediments were laid down on a relatively unstable shelf in transitional or deltaic and shallow water marine environments. Isopach-lithofacies maps indicate that clastic sediments become coarser and more dominant northward toward the Appalachian Piedmont, while carbonates and finer clastics are the major lithologies southeastward near the Suwannee Channels and southward toward the Gulf. The principal source area of those terrigenous materials is considered to be the Southern Appalachians. Stratigraphic analysis indicates that only epeirogenic movements affected the area during the Early Tertiary time. Several minor disconformities have been recognized at the outcrop area, but they are generally not recognizable in the subsurface in panhandle and peninsular Florida, except at the contacts of the Ocala Group which show unconformable relationships with beds lying above and below. The fact of gradual but steady spreading of the nonclastic facies northerly and westerly over the clastic facies during early Tertiary time may be the result of continued marine transgression. Some spor5adic regressions occurred during Paleocene and Eocene time as manifested by the presence of local and regional unconformities. Paleogeographic maps of the successive Paleocene and Eocene stratigraphic units studied are reconstructed on the basis of the series of isopach-lithofacies maps, lithologic and paleontologic data, and ecologic and environmental conditions inferred from this study.