Creating a livable and sustainable urban future requires collaboration and contributions from multiple disciplines and sectors. While previous studies have primarily focused on the roles of urban design, architecture, technology, or agriculture, the role of interior design is often underestimated. Interior design can profoundly impact the overall development of cities through its influence on citizens’ behaviors and emotions. Interior design can connect the built environment and its occupants well to promote well-being and facilitate human advancement [1]. Optimal interior design could elevate human behavior, inspiring people to do better and improve, which is a critical factor in making a livable urban environment. Interior designers can create a well-being environment by generating a comfort zone through practical criteria. The primary objective of this study is to fill a knowledge gap on the role of interior design in fostering the development of a livable and sustainable urban environment. By exploring how interior design principles, strategies, and elements can act as catalysts for positive changes in urban areas, this chapter delves into how interior design contributes to creating functional, aesthetically pleasing, and environmentally responsible interior spaces that enhance cities’ overall livability and sustainability. The outcome of this paper can benefit other professionals, including urban designers, planners, environmentalists, architects, and citizens, who consider it when choosing interior design as an essential catalyst in forging a livable and sustainable urban future.