This chapter gives a survey of selected studies where the principles of coevolution have been applied for real-world problem solving. We start our presentation with a general introduction that links previous Chaps. 2 and 3 in order to emphasize how real-world problems have to be formulated to one of the two settings of cooperative and competitive coevolution for problem solving. We focus on several problem domains that include business, economics and public policy, entertainment games, engineering, logistics and transportation, and software, systems, and software services. We have made the attempt to present a diverse selection of applications of coevolution of specific real-world problems to highlight the broad applicability of coevolutionary systems. In general, problem-solving formulations in these studies can be categorized as optimization and learning. Our choice of presentation for this literature review is then directed towards the individual studies. For each study, we give a summary on the nature of the specific real-world problem, its importance, how it is abstracted so that an optimization or learning setting can be formulated, and then how coevolution is applied for problem solving. We conclude with a discussion about the general use of coevolutionary principles in these real-world problem-solving settings.