In southeastern Saskatchewan, the Mississippian Mission Canyon Formation was deposited in the northern platform margin of the Williston Basin and includes, from bottom to top, Tilston Beds, Alida Beds, Kisbey interval and Frobisher Beds. The formation is dominated by carbonate lithofacies, subordinate evaporites and economically important sandstone lithofacies (Kisbey interval) also occur within the formation. Cores, cuttings, wireline logs and petrographic studies of these strata in the research area have allowed identification of lithologic attributes, cyclicity and diagenetic features of the strata. Eight lithofacies have been identified: i) oolitic and bioclastic packstone/ grainstone (Facies PG), ii) oncolitic rudstone (Facies RD,) iii) bioclastic & oolitic mudstone/wackestone (Facies MW), iv) dolomudstone (Facies DS), v) sandstone/ siltstone (Facies SS), vi) sandy dolomudstone (Facies SD), vii) sandy packstone/ grainstone (Facies SP) and viii) anhydrite (Facies AH). The overall depositional setting can be summarized as shallow-marine environment characterized by bioclastic and oolitic carbonate subtidal sand shoals with a landward lagoonal to tidal mud-flat system. The sandstone lithofacies of the Kisbey interval suggests a connection between tidal creeks that cut a carbonate-dominated shallow platform and a possibly fluvial system that brought the detrital grains into the basin. The temporal lithofacies arrangement of the studied stratigraphic interval shows clear vertically-stacked rhythmic units defined by shallowing-upward cycles of basal subtidal lithofacies (PG, RD,SP, MW) grading to restricted lagoonal / tidal mudflat deposits (MW, DS, SD, SS & AH). Fischer Plot analysis of these rhythmic units suggests higher (4th to 5th) order Milankovitch cycles that can be grouped into six, possibly 3rd order depositional cycles. These 3rd-order cycles appear to correlate well with the Mississippian cyclothems, and thus attributable to eustatic sea level changes. The diagenetic products, their paragenetic sequence and effects on the reservoir quality of the strata have been discerned. The diagenetic products and their paragenetic sequence are as follows: micritization and micrite envelope, fibrous calcite cement, bladed calcite cement, fine crystalline dolomite (dolomite event 1), dissolution event 1, compaction, fracture, equant calcite cement, fine to medium crystalline dolomite (dolomite event II), anhydrite cement 1, dissolution event II, and anhydrite cement II. Four major diagenetic processes profoundly affected porosity development of the Mission Canyon Formation. Cementation, compaction, dolomitization and dissolution were active throughout the evolution of the formation. Besides these diagenetic features, primary and secondary porosities that define the reservoir qualities of the sections were identified. They include, interparticle, intraparticle, intercrystalline, fenestral, fracture, vuggy and moldic porosities. Different degrees of porosity-destroying and porosity-enhancing features result in porosity and permeability differences among the lithofacies units of the Mission Canyon Formation. The Tilston Beds and Kisbey interval show good porosity (Tilston: average 19.7%; Kisbey: average 18.2%) and permeability (Tilston: average 33.7 millidarcies; Kisbey: average 199.3 millidarcies) while the Alida Beds and Frobisher Beds exhibit moderate porosity (Alida: average 14.5%; Frobisher: 11.3%) and permeability (Alida: average 11.0 millidarcies; Frobisher: average 45.5 millidarcies), the permeability correlates positively with the porosity. The tidal channel and carbonate sand shoal show good porosity and permeability.