With the disaggregation of complex products into interchangeable modules, modularity has become a revolutionary innovation paradigm in many industries. This chapter addresses modular innovation in the consumer electronics, automotive, and furniture industries that aims to improve product adaptability, sustainability, and customer experience. Illustrative case studies on Fairphone, Volkswagen’s MQB/MEB platforms, and IKEA’s modular living solutions demonstrate that these effects include reduced production costs, extended product lifespans, and enhanced consumer satisfaction. The results show that modularity supports operational performance and aligns with sustainability agendas and personalisation trends. The chapter concludes by arguing that modular innovation is a building block of competitive advantage and presents future discussions on digital integration, alignment with the circular economy, and cross-industry modular ecosystems.