The construction industry is under growing pressure to adopt sustainable and eco-friendly building materials. This paper explores the potential of using banana fibre and eggshell powder—both common household waste products—as reinforcing agents in sun-dried clay bricks to enhance their compressive strength. The study investigates the effect of varying eggshell powder content (0%, 5%, 10%, and 15%) while keeping banana fibre constant at 0.35% by weight, 50 mm in length, and a 1:20 aspect ratio. Experimental results showed that replacing 10% of clay with ESP yielded the highest compressive strength of 2.65 N/mm2, compared to 1.60 N/mm2 for conventional sun-dried bricks—an improvement of approximately 65.63%. The findings highlight the environmental and economic benefits of repurposing biodegradable waste while also addressing the limitations of incorporating these materials in construction.