Circularity assessment and monitoring have become a core research topic in academic societies, as well as a basis for developing economic development measures. Despite the circular economy (CE) being a game-changer for the agro-food sector, little effort has been made to identify its level of circularity. In order to achieve the transition to a CE, stakeholders and industry professionals must be provided with appropriate indicators, tools and methods. Due to the complexity of CE measurement, it is necessary to devise indicators, methods and tools that are tailored to each industry. The objective of this review article is to identify the indicators and tools required for assessing the level of circularity in olive oil mills. This research collected data regarding available CE indicators at the company and product levels, as well as those applicable to the agro-food industry. As a result, a list of indicators appropriate to the needs of olive mills has been developed that could be used to measure the level of implementation of circular practices in this industry. The main conclusion reached is that once indicators are defined, they should be compared or combined with life cycle assessment methodologies to determine their applicability and effectiveness. There is no doubt that olive oil plays a significant economic, environmental and social role throughout the Mediterranean region. Hence, evaluating the CE is essential to demonstrate the effectiveness of current policies.