This volume comprises a selection of papers originally presented at the 6th International Workshop on Branching Processes and Their Applications (IWBPA24), held from April 8 to 12, 2024, in Badajoz, Spain. The contributions cover a broad spectrum of both theoretical and applied topics within the field of branching process theory. Together, they highlight the ongoing vitality and significance of this research area--not only in advancing core mathematical theory but also in tackling emerging challenges across diverse applied fields such as Epidemiology, Biology, Genetics, and Population Dynamics.

The topics explored in this volume can be broadly categorized into the following areas:

1. Markovian and non-Markovian branching trees

2. Branching processes in Biology, Genetics, and Epidemiology

4. Branching random walks

5. Special branching models

6. Statistical inference in branching processes

Serving as a valuable resource for current research, this volume also identifies numerous open problems, paving the way for future developments in both theoretical and applied contexts.