By-product synergy (BPS) is the matching of under-valued waste or by-product streams from one facility with potential users at another facility to create new revenues or savings with potential social and environmental benefits. This presentation will describe by-product synergy networks among industries and municipalities in the United States and abroad. These networks have been started and developed in places like Chicago, the Gulf Coast, and the UK. Examples will be provided that delineate the results these networks are able to achieve in metrics such as energy use and waste reduction. Opportunities for innovation in business processes will also be described through development of new product lines.