This study is focused on Life Cycle Assessment (LCA) method to support the waste valorisation to bio-based composite material in French olive oil circular economy (CE). Its aim is to demonstrate how to shift from a traditional linear production to a circular olive production system that recovers materials from organic residues. On one hand, a comprehensive environmental assessment of eleven scenarios representing French olive oil production is performed. A comparison of the environmental performance from a life cycle perspective is made among the different scenarios. This analysis is conducted from a business-as-usual perspective: a linear production without valorisation of by-products. On the other hand, the environmental performance of an Olive Pomace based-composite for the decking sector is evaluated. The last part addresses the connection of the LCA from a business-as-usual perspective with the LCA of olive pomace valorisation to demonstrate how LCA can support the transition from traditional linear to circular olive production and can feed decision-making process. In the transition to a circular system in which waste is recovered for recycling, a new product is created that can replace another product with the same function. The results confirm that LCA method contributes to objectify the expected environmental benefits of the circular economy approach.