In science and engineering, differential equations play an important role in all models and systems. This topic is very special due to the variety of classes for differential equations, and the fact that each class is essential while studying applied sciences and engineering. The main aim of this Special Issue is to create a collection of state-of-the-art research studies on Special Issues in differential equations with applications in science and engineering to provide researchers with the most recent advances in these topics, which are very important in modeling various scientific phenomena. This Special Issue, entitled "Special Topics in Differential Equations with Applications", has published important research articles in the field of differential equations, authored by several well-known mathematicians and scientists from diverse countries worldwide, such as the USA, Ireland, Italy, France, Slovakia, Greece, Austria, Romania, Bulgaria, Malaysia, Tuerkiye, Tunisia, Pakistan, India, China, Jordan, Sudan, Morocco, Egypt, Algeria, China, Russia, and Saudi Arabia.