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.