The two-volume LNCS set 14813 and 14814 constitutes the refereed proceedings of the 24th International Conference on Computational Science and Its Applications, ICCSA 2024, held in Hanoi, Vietnam, during July 1-4, 2024. The 53 full papers, 6 short papers and 3 PHD showcase papers included in these volumes were carefully reviewed and selected from a total of 207 submissions. The papers focus on the following six sub-areas within Computer Science and its Applications: Computational Methods, Algorithms and Scientific Applications; High Performance Computing and Networks; Geometric Modeling, Graphics and Visualization; Advanced and Emerging Applications; Information Systems and Technologies & Urban and Regional Planning.