The thia‐Michael addition reaction has been demonstrated to be a highly powerful tool in organic synthesis. Indeed, the influential nature of this reaction has been well‐established in the fields of medicinal chemistry, catalysis, drug discovery, and materials science. The emergence of numerous synthetic strategies that take advantage of thia‐Michael addition reactions of electron‐deficient alkenes has unleashed countless opportunities for the design and synthesis of diverse biologically relevant organosulfur compounds. However, despite myriad potential synthetic applications, there has not been any exclusive reviews of the thia‐Michael addition reaction. Therefore, this Focus Review plots the journey of the thia‐Michael addition reaction in organic synthesis, and is categorized according to catalyzed and catalyst‐free thia‐Michael addition reactions.