Abstract: The selective activation and functionalization of carbon–hydrogen (C–H) bonds represents an important area of organometallic chemistry because it provides opportunities to transform relatively unreactive C–H bonds directly into synthetically valuable functionalities. This paper examines the development, mechanistic foundations, and catalytic applications of organometallic C–H bond activation, with particular emphasis on transition-metal-mediated processes. The discussion traces the historical evolution of the field from early observations of electrophilic and oxidative activation to the development of increasingly sophisticated catalytic systems. Particular attention is given to electrophilic C–H activation and oxidative addition, highlighting their mechanistic relationships rather than treating them as completely independent pathways. The Shilov system is examined as an important example of platinum-mediated alkane activation and functionalization, involving C–H activation, oxidation, and subsequent product-forming steps. The paper further discusses oxidative addition of aromatic and aliphatic C–H bonds and the contribution of transition-metal complexes containing platinum, ruthenium, rhodium, and iridium to the development of C–H activation chemistry. Catalytic applications involving carbonylation, insertion reactions, site-directed functionalization, and alkane dehydrogenation are also considered. The discussion demonstrates that metal electronic properties, ligand environments, substrate structure, directing groups, and reaction conditions collectively determine the mechanism, selectivity, and catalytic efficiency of C–H functionalization. Overall, organometallic C–H activation provides an important platform for developing more direct approaches to molecular modification, although improvements in catalyst stability, selectivity, efficiency, and practical applicability remain important areas for continued research.