Waste cooking oil (WCO) is a major environmental contaminant that is produced in large quantities and then discharged into the environment, mostly in China and India. Large volumes of WCO being disposed of are causing several detrimental environmental problems, including clogged sewers, trouble for wastewater treatment plants pre-treating sewage, and pollution of water and land if WCO is dumped in municipal solid waste dumps. WCO has been linked with atherosclerosis, hypertension, liver diseases, and Alzheimer's disease. This article focuses on the process of turning waste cooking oil (WCO) into sustainable products like cement and concrete, bioplastics, plasticizers, animal feedstocks, fermentative substrates, green solvents, grease, bio-lubricants, surfactants, polyurethane, and resin for 3D printing. These organic materials can help ensure that used WCO is disposed of properly and thus minimize the ensuing health risk.