Geological studies over the Arabian Peninsula were initiated in the 1930s, and 30 years later an area equivalent to 3.5 million km2 was covered, laying the groundwork for the stratigraphic nomenclature of the Arabian Peninsula. Since then, not much has changed in terms of formation ages and formation naming, where subsequent authors largely took the results of the earlier work for granted. This thesis will evaluate the sedimentological and depositional facies of exposed rock units in the countries of Kuwait and Bahrain with the objective of developing a depositional facies model that can explain the complex facies architecture. During this study, it was revealed that the exposed rock units in Kuwait at the Jal Az-Zor escarpment all belong to the Lower Fars Formation (also known as Kuwait Formation), whereas previous interpretations assigned these rocks to Ghar, Lower Fars, and Dibdibba formations. This study further revealed that the depositional environment of the Lower Fars Formation is dominated by marginal marine deposits manifested by a riverine to tidally influenced estuary setting, which is contrasting to the fluvio-deltaic setting within previous interpretations. The origin of the NE-SW trending Jal Az-Zor escarpment has been disputed in Kuwait, where it has been proposed either a surface erosion expression, or an underlying unspecified basement fault. Detailed 2D seismic processing and interpretation revealed unprecedented structural features such as detachment, tight concentric and recumbent folds, thrust faults, and fault propagation folds. Tectonic deformation of the Kuwait Formation within the subsurface at the Jal Az-Zor escarpment reflects the initial stage of fault propagation folding resulting from the Kuwait Arch plunge towards the south of the Jal Az-Zor area. Kinematic analysis suggests that the Jal Az-Zor escarpment is a surface expression of a principal displacement zone that is dominated by dextral strike-slip motion and is found to play a major role in the rotation of the Arabian Plate since the early Pleistocene (Calabrian). Throughout this study, it has been observed that detachment could have occurred along the Dammam and Rus formations. Subsequent analysis of the composition of these two formations indicates that the Rus Formation exhibits a greater potential for generating detachment surfaces. The Rus Formation was earlier thought to be dominated by evaporites which favours detachment and was considered a regional seal covering the majority of the Arabian Peninsula. However, detailed sedimentological field work at the Horse-Racing Club outcrop in Bahrain and subsequent published borehole data suggest that the Rus Formation in Bahrain is predominantly composed of dolomites. These changes in understanding facies types and spatial distribution open the door for an in-depth evaluation of the whole Arabian Peninsula facies distribution. The complexity of the Arabian Peninsula's sedimentology and structural development was highlighted in this thesis, demonstrating the need for a re-evaluation of the region's facies nomenclature and tectonic history in light of current geological knowledge and newly available data.