ortho-Alkynylarylcarbonyl compounds, including ketones, aldehydes, carboxylic acids, carboxylate esters and amides, have served as useful building blocks for synthetic chemists to prepare numerous classes of important molecules. Various synthetic conversions starting from ortho-alkynylarylcarbonyl precursors are made possible by their unique and enabling structures embedded with reactive carbonyl and alkyne functional groups. These functional groups can be converted directly and independently to other compounds by several reactions. This review highlights the use of these compounds as common precursors for the divergent synthesis of valuable molecules. Moreover, these ortho-alkynylarylcarbonyl compounds can be decorated with other functional group tethers which can lead to an even greater diversity of molecular scaffolds.