The Circular Economy (CE) is widely known as a possible solution to address sustainable development in the manufacturing sector. This paper investigates the adoption status of CE in the steel industry of Thailand. A survey questionnaire was designed, validated, and distributed among Thai steel manufacturing companies. The result of the study indicates that some of the participants’ organization had already implemented the CE. The implementation success of CE is moderate-high. The CE is found to be implemented mainly at the departmental level, rather than across the entire organization. The main drivers of CE implementation are internal motivations, including environmental awareness, long-term sustainable development, and cost savings from material circularity. Furthermore, reducing the environmental impact on external stakeholders is the main CE external driver. A lack of proper training and knowledge, too much effort required, and a lack of support from top management are the main barriers to implementing the CE. This study offers direct benefits for academics, researchers, and steel manufacturing companies who are interested in CE implementation. It also shows the initial evidence of CE adoption in the Thai steel manufacturing industry.