This proceedings volume compiles papers presented at the 5th International Conference on Mathematics and its Applications in Science and Engineering – ICMASE 2024, held on September 16–18, 2024, by the Polytechnic Institute of Coimbra, Portugal. The ICMASE 2024 was a hybrid conference, featuring both in-person and virtual attendance. The works in this volume explore recent developments in the application of mathematics to science and engineering, focusing on mathematical and computational modeling of real-world problems. Topics include algebra and number theory, analysis, geometry, statistics, computational and discrete mathematics, as well as their intersections with engineering applications. Additionally, educational aspects of mathematics in engineering fields are addressed. This volume is intended for researchers, practitioners, and graduate students, particularly those interested in advanced methods for applying mathematics across various contexts and fields.