This introduces sustainable product development in the context of increasing global resource consumption, ecological challenges, and societal expectations. It argues that sustainability must serve as the foundation of engineering practice rather than an additional pathway. Legal frameworks and international standards act as key drivers alongside societal demands for sufficiency, efficiency, consistency, legality, lifecycle orientation, and sustainable design. The historical evolution of sustainability is traced from early forestry and resource balance concepts through the Brundtland Report and UN Sustainable Development Goals to the modern sustainability triangle linking ecological, economic, and social dimensions. Various product types (primary, cyclical, relative, functional, partial, and apparent) are discussed within frameworks such as Maslow’s hierarchy of needs and value engineering. Social sustainability is addressed via Corporate Social Responsibility, shared economy models, frugal innovations, and approaches like IKIGAI that link societal well-being with design. Methodological challenges are explored by comparing classical product development models with agile and exploratory approaches. Emphasis is placed on early concept phases, where most environmental impacts are determined, underscoring engineers’ responsibility to integrate sustainability from the outset. Overall, the chapter frames sustainable product development as a technical and ethical imperative demanding systematic methods, legal compliance, and conscious responsibility throughout the product lifecycle.