Our world faces critical environmental challenges, such as greenhouse gas emissions, natural resources depletion, and solid waste disposal. Concrete, the second most consumed material on Earth after water, is responsible for 8–10% of global CO2 emissions, primarily stemming from clinker production. Meanwhile, the substantial volume of concrete waste (CW) generated throughout its lifecycle, along with the rising global demand for concrete due to rapid urbanization, exacerbates these pressing concerns. Accelerated carbonation of CW is an effective method to consume CW and sequester long-lasting CO2. Upcycling carbonated CW to substitute aggregate and cement in sustainable construction materials can also benefit in reducing CO2 emissions and conserving natural resources. However, bridging the gap between research and practice by promoting the effective use of carbonated concrete waste in the construction sector is the key for achieving this goal. This chapter thus discusses advancements in the carbonation of concrete waste, focusing on the carbonation mechanism and its strategic application to various recycled CW fractions, namely recycled coarse and fine aggregates, as well as recycled concrete powders.