C–S bond activation, cleavage and transformations by means of transition metal compounds have recently become more and more important in the petroleum industry and synthetic chemistry. Homogeneous transition metal compounds have been investigated in order to provide the fundamental insight into the C–S bond cleavage in problematic organosulfur compounds such as thiophene, benzo- and dibenzothiophene derivatives. Rendering transition-metal mediated reactions with organosulfur compounds catalytic may provide promising routes to deep hydrodesulfurization of petroleum feedstocks, and offer potentially useful synthetic protocols for cross-couplings and biomimetic organic synthesis. During the last few decades increasing work was documented on C–S bond activation and transformations by means of transition metal compounds. This review summarizes the recent advances in C–S bond cleavage via the insertion of transition metals into the inert C–S bonds of these problematic organosulfur compounds, and transition-metal mediated C–S bond transformations via C–S activation through cross-couplings of thioesters, ketene dithioacetals, sulfonyl chlorides, and other diverse organosulfur compounds.