<p>The Upper Paleozoic strata of the Ordos Basin represent a significant exploration target for tight gas and coal-measure gas in China, where lithological associations and fracture characteristics play a critical role in reservoir evaluation. Based on integrated data from core samples, thin sections, well logs, and rock mechanics experiments, this study systematically investigates the types, distribution patterns, and fracture development characteristics of lithological associations in coal-measure source rocks within the study area. Four main lithological associations are identified: sandstone–coal, mudstone–coal, limestone–coal, and bauxite–coal assemblages, each exhibiting distinct spatial zonation. Well-log response analysis provides a quantitative basis for identifying these association types and mapping their planar distribution. Rock mechanics experiments reveal that the fracturing sequence of different lithologies under stress is as follows: coal, fine-grained quartzose clastic rocks (mudstone), quartzose clastic rocks (sandstone), and limestone. Fracture development is strongly influenced by lithological associations: high-angle open fractures dominate in sandstone–coal assemblages; fractures in mudstone–coal assemblages are commonly filled with clay minerals; fracture intensity in limestone–coal assemblages is controlled by limestone type, with bioclastic limestone exhibiting more developed fractures; and fractures in bauxite–coal assemblages are typically filled with bauxitic minerals. Based on these findings, a hierarchical classification scheme for dominant lithological associations was established, and a distribution map was compiled. This work provides a scientific basis for predicting favorable zones and evaluating fractured reservoirs in unconventional hydrocarbon exploration of the Upper Paleozoic Ordos Basin.</p>