This book constitutes the proceedings of the 15th International Workshop on Statistical Atlases and Computational Models of the Heart, STACOM 2024, held in conjunction with the 27th International conference on Medical Image Computing and Computer Assisted Intervention, MICCAI 2024, in Marrakesh, Morocco in October 2024. The 48 regular workshop papers included in this volume were carefully reviewed and selected from 64 paper submissions. They focus on Regular Papers; Multiclass Bi-Atrial Segmentation Challenge and Cardiac MRI Reconstruction Challenge.