The increased energy demands have placed enormous pressure on finite fossil fuels. These fossil fuels consumption has reached 15 billion million tonnes (MT) annually, which has contributed to 37.55 billion MT of carbon dioxide emissions in 2023. These emissions lead to global warming, climate change, and other associated changes. Therefore, there is a need for carbon sequestration for a better tomorrow. Fly ash (FA), a waste product generated by coal-fired electric and steam-generating plants is a potent waste that can be used for different practical uses. Moreover, it is estimated that around 500–600 MT of FA is generated annually. This waste can be tapped for resource recovery. In fact, FA is an emerging building material that can also contribute to carbon sequestration. This chapter explores FA-based bricks, concrete, and other building materials for sustainability. These materials require lesser cement and other natural resources. The produced materials with comparable strength, stability, and density could synergize with the conventional building materials and could be a small step towards sustainability with circular economy.