AbstractEach year, approximately million tons of waste is generated from eggshells disposed of in landfills. This waste is challenging to manage because of the odor and microbiological development. However, eggshells have potential applications as a solid byproduct. They can be modified and used in various industries such as metal, polymer and ceramic composites, in the production of biodiesel, heavy metal absorption from wastewater, and even as a biomaterial to substitute bone tissues. Furthermore, eggshells can be used as a cheap adsorbent for the treatment of contaminated waterways. They are also a great source of calcium and fertilizer for plants, animals and humans. Chicken eggshells can even be used as a catalyst for converting waste frying oil into biofuel. This review highlights the challenges and opportunities of eggshell waste valorization in the food industry. © 2024 Society of Chemical Industry.