<p>The study analyzes the technical efficiency of 54 Greek wineries from 2016 to 2022 using constant and variable rate of return to scale models and data envelopment analysis with a cost-based approach. The results reveal that only a small proportion of wineries (14.81–22.22%) achieved perfect efficiency, indicating inefficiencies in resource management and production methods. However, under variable scale conditions, up to 48% of wineries achieved efficiency, suggesting that improvements can be made by optimizing scale and implementing more effective management practices. This study identifies efficient wineries and provides strategic recommendations to enhance the competitiveness of the Greek wine sector through innovation, investment, and improved management capacity. To the best of the authors’ knowledge, this is the first financial statement analysis of technical efficiency in the Greek winery sector. Measuring efficiency is essential for understanding the performance of wineries and ensuring the long-term environmental, economic, and social sustainability of the industry.</p>