<p>The increasing demand for construction materials has created a need for sustainable alternatives to conventional cement and natural aggregates. Rice husk ash (RHA) and recycled coarse aggregate (RCA) are two waste-derived materials with significant potential for sustainable concrete production. RHA is obtained from agricultural waste and can act as a supplementary cementitious material, while RCA is produced from construction and demolition waste and can partially replace natural coarse aggregate. This paper presents a concise review of the influence of RHA and RCA on the performance and sustainability of concrete. The reviewed literature indicates that RHA can contribute to strength development and pore refinement when appropriately processed, whereas RCA can reduce the consumption of natural aggregates and divert construction waste from disposal. However, excessive RCA may increase water absorption and reduce mechanical performance, while the properties of RHA are strongly influenced by its processing conditions. The combined use of RHA and RCA therefore requires careful mix design and material quality control. The study concludes that the appropriate combination of these materials can contribute to sustainable concrete and circular construction.</p>