The article reviews the advancements in solid-state electrolytes (SSEs) for sodium-ion batteries (SIBs), highlighting their potential to enhance energy density and safety compared to liquid electrolytes. SIBs, due to their lower cost and abundant sodium resources, have gained attention as a viable alternative to lithium-ion batteries (LIBs) for large-scale energy storage. However, SIBs face challenges such as lower energy density and shorter development time compared to LIBs. The electrolyte, a critical component, influences the energy density and rate capability of SIBs. While water-based and organic solvent electrolytes provide stable cycling performance, they have limitations in voltage and safety. Solid-state electrolytes, which offer better processability, safety, and compatibility with sodium anodes, have emerged as a promising solution. They can achieve higher energy densities and have a broader electrochemical window, making them suitable for high-voltage cathodes. The review discusses various types of SSEs, including inorganic, polymer, and plastic crystal electrolytes, and addresses key issues such as low ionic conductivity, narrow electrochemical stability windows, and poor electrode contact. Despite these challenges, the increasing number of publications indicates growing interest in SSEs for SIBs.The article reviews the advancements in solid-state electrolytes (SSEs) for sodium-ion batteries (SIBs), highlighting their potential to enhance energy density and safety compared to liquid electrolytes. SIBs, due to their lower cost and abundant sodium resources, have gained attention as a viable alternative to lithium-ion batteries (LIBs) for large-scale energy storage. However, SIBs face challenges such as lower energy density and shorter development time compared to LIBs. The electrolyte, a critical component, influences the energy density and rate capability of SIBs. While water-based and organic solvent electrolytes provide stable cycling performance, they have limitations in voltage and safety. Solid-state electrolytes, which offer better processability, safety, and compatibility with sodium anodes, have emerged as a promising solution. They can achieve higher energy densities and have a broader electrochemical window, making them suitable for high-voltage cathodes. The review discusses various types of SSEs, including inorganic, polymer, and plastic crystal electrolytes, and addresses key issues such as low ionic conductivity, narrow electrochemical stability windows, and poor electrode contact. Despite these challenges, the increasing number of publications indicates growing interest in SSEs for SIBs.