This book offers a comprehensive introduction to electrochemistry and its applications in electroanalysis. It begins by establishing the fundamental principles before guiding readers through the most widely used electroanalytical techniques, their practical applications, and methods for reliable data analysis. Sensor design and fabrication are explored in detail, including essential equipment such as potentiostats, electrodes, and electrochemical cells, along with key considerations for experiments conducted in the laboratory, with real samples, or on site.The book also examines a broad range of analytes, from heavy metals and environmental contaminants to healthcare-related targets, highlighting their importance, regulatory limits, and representative electroanalytical outputs. A dedicated chapter on biosensors introduces their components, fabrication strategies, and examples from current research.Looking toward the future of the field, the book explores the rapidly expanding role of additive manufacturing and 3D printing in creating bespoke electrochemical sensors. It concludes with an overview of wearable electroanalytical technologies, discussing strategies for sensor integration and the challenges of adapting devices for use on different parts of the body.