In recent years, machine learning has rapidly evolved from a theoretical research domain into a core driver of innovation across industries, shaping decision-making processes in finance, healthcare, criminal justice, and beyond. As these intelligent systems increasingly affect real lives and critical outcomes, the demand for transparency and accountability in their decisions has never been more urgent. This demand brings to the forefront a critical yet often overlooked aspect of machine learning—interpretability. This book, Interpretable Machine Learning, is born out of a growing need to bridge the gap between powerful predictive performance and human understanding. While complex "black-box" models can deliver exceptional accuracy, they often do so at the cost of explainability— leaving stakeholders, regulators, and even model developers in the dark about why a model makes a specific prediction. Interpretability addresses this challenge by opening up the inner workings of these models, making them more transparent, trustworthy, and aligned with ethical and legal frameworks. The book is structured to provide a comprehensive, end-to-end guide to the theory, techniques, tools, and applications of interpretability and explainability in machine learning. Whether you're a data scientist aiming to implement interpretable models, a policymaker looking to understand regulatory implications, or a researcher seeking to explore new directions in this vital field, this text offers depth and clarity across all levels. We begin with foundational concepts, including the rationale behind interpretability, its difference from explainability, and various types and approaches. Through real-world case studies—from financial services and healthcare to autonomous systems—we highlight the critical importance of interpretable models in high-stakes environments. Later chapters delve into hands-on methods such as LIME, SHAP, and advanced explainability frameworks, offering practical insights supported by implementation examples in Python. Special attention is given to the challenges and trade-offs involved in balancing interpretability with performance, as well as the ethical and regulatory landscape that increasingly shapes AI deployment. By incorporating both theoretical discussions and hands-on practice, the book aims to equip readers with not just the "how," but also the "why" behind interpretable machine learning. As machine learning continues to influence society in profound ways, interpretability will not remain a niche interest but will become a cornerstone of responsible and human-centered AI. It is our hope that this book serves as a useful and timely guide in that ongoing journey.