Geometric optics (GO)-based solar light management strategies use optical phenomena like specular reflection, refraction, and total internal reflection to optimize solar energy utilization across buildings, industry, and agriculture. These strategies improve energy efficiency in buildings by using optics systems for renewable energy generation, such as integrated photovoltaics, photothermal applications, or direct utilization of solar energy for daylighting applications. In agriculture, GO can provide precision-controlled greenhouse lighting and optics-enabled renewable energy systems for improved light management in agrivoltaics. In industry applications, solar light management is crucial for many sectors. The broad adoption of GO in industries can be exemplified by applications like solar photoreactors for chemical processing, solar tracking, biofuel production, carbon capture, hydrogen generation, and generating high-value compounds like pharmaceuticals, food additives, pigments, etc. This chapter explores the importance of GO in these technologies, their design principles, and the challenges of integrating GO-based solutions, highlighting their role in advancing sustainable development goals.