Halide perovskites have attracted widespread attention over the past two decades owing to excellent charge carrier dynamics and photovoltaic properties. The conversion efficiency of solar cells based on these materials has reached up to 26% in the past years making them the leading materials in photovoltaics today. Enhanced performance and diversification into different types of solar cells have opened new interest in low-bandgap perovskite-based solar cells. This chapter explores the latest developments in the area of low-bandgap perovskite solar cells detailing the different materials involved, the device architecture, and the factors determining performance enhancement. The constituent elements involved in perovskite engineering is discussed, including formamidinium-based perovskites, cesium-based perovskites, lead–tin double perovskites, and mixed halide perovskites. The device design strategies are elaborated covering sequential deposition, additive engineering, interfacial and bandgap engineering, and tandem configurations. Finally, the performance enhancement approaches and optimization schemes involving controlling the defect density, improving charge extraction, reducing recombination losses, and creating multi-junction arrangements are reviewed further to provide a holistic impression on the latest updates on low-bandgap perovskite solar cells.