This review covers the development and advances in transition-metal-catalyzed aryl-aryl bond formation by direct arylation as well as its application to the synthesis of important compounds including natural products, pharmaceuticals, catalyst ligands and materials. Studies focused on developing milder, lower temperature direct arylation reactions are discussed in addition to recent studies that focused on the fine-tuning of catalyst systems to allow for the use of more inexpensive and industrially attractive aryl chlorides. It is emphasized that these studies will help both synthetic and material chemicals a great deal, making direct arylation a valuable tool for diverse academic and industrial applications.