Metal ions exist globally. Therefore, the study of the design strategies, mechanistic insights, and applications of fluorescent Schiff base sensors for metal ion detection constitutes an active topic of research. Further, theoretical studies on these systems using various spectroscopic techniques add new flavor in terms of providing a better understanding of the photo-electronic properties of Schiff base sensors and their complexes with metals. The presented review article starts with the general introduction of fluorescent Schiff base sensors for metal ion detection, and consists of two main sections. The first section illustrates the strategies and different mechanistic insights into metal ion detection using Schiff base sensors. The second section demonstrates the application of fluorescent Schiff base sensors in metal ion sensing, biomedical imaging, environmental monitoring, and optoelectronic systems. Additionally, a summary of the reviewed fluorescent Schiff base sensors is presented in a table format. Finally, the conclusion and future scope of fluorescent Schiff base sensors for metal ion detections are discussed.