An important branch of nonlinear analysis theory, applied in the study of nonlinear phenomena in engineering, physics, and life sciences, is related to the existence of fixed points of nonlinear mappings, the approximation of fixed points of nonlinear operators, of zeros of nonlinear operators, and the approximation of solutions of variational inequalities. This special issue is focused on the latest achievements in these topics and the related applications.The aim is to present the newest and extended coverage of the fundamental ideas, concepts, and important results of the topics below. Topics of interest include, but are not limited to the following.