Circular supply chains (CSC) are one of the pillars of the circular economy (CE). Previous studies have shown that closing the material loop helps to recover value in the supply chain. The aim of this study is to evaluate selected supply chains in the fashion industry using a proprietary circularity index. This exploratory study identifies best practices in circular supply chains and evaluates three supply chains in the fashion industry. We seek answers to three research questions: (1) What circular supply chain solutions and best practices exist in the fashion industry? (2) How can the circularity of the fashion supply chain be assessed? (3) To what extent are selected fashion brands implementing circular supply chain principles? We used an expert survey with a Likert scale to rank solutions and best practices. The results of the expert survey were statistically analysed to determine the consensus of the expert opinion. We used our own circularity index to assess supply chains in the fashion industry. Circularity was evaluated in three fashion supply chains. We calculated a circularity index for each. Based on this, we found that two brands have a circular supply chain that can be further optimised in the pursuit of excellence, and one brand has the potential to move towards a circular supply chain. We defined suggested actions that will fill the circularity gap. The fashion industry implements solutions toward cicularity and sustainable development, the list of such solutions can be formulated as the basis for cicularity evaluation, gap identification, and improvement suggestions.