This edited book provides a comprehensive framework for the integration of mathematical methodologies into biological research, emphasizing applications that directly address topics related to SDG 3 (Good Health and Well Being) and SDG 6 (Clean Water and Sanitation). From the mathematical modeling of infectious diseases to the design of smart agricultural systems, each chapter presents key global issues where mathematical analysis is a powerful tool for driving progress. This work emphasizes the importance of mathematical models in predicting outcomes, optimizing interventions and understanding the dynamics of complex biological systems. The central theme of the book is the application of mathematical methods, ranging from deterministic models, stochastic processes, fractional calculus and machine learning algorithms to biological problems, framed in the context of sustainability. Each chapter is crafted to showcase how mathematical models not only enhance our understanding of biological phenomena but also play a pivotal role in developing solutions to global issues such as pandemics, environmental degradation and resource management.