This book constitutes the refereed proceedings of the 11th International Conference on Algorithms and Discrete Applied Mathematics, CALDAM 2025, held in Coimbatore, India, during February 13-15, 2025. The 30 full papers included in this book were carefully reviewed and selected from 89 submissions.The conference had papers in algorithms and complexity, discrete applied mathematics, computational geometry, graph theory, graph colouring, graph partition, and domination in graphs.