This study aims to evaluate the financial performance of 36 companies from different sectors listed on Borsa Istanbul (BIST) Sustainability Index for the years 2021, 2022, and 2023 using multi-criteria decision-making (MCDM) methods. BIST companies represent Turkey's most actively traded and transparent companies. These companies constitute a suitable sample for our study because they provide reliable and accessible financial data and include Turkey's largest and most institutionally developed companies. Eight financial criteria were selected as performance measures, namely Price-to-Earnings ratio (P/E), Return on Capital Employed (ROCE), Tobin’s Q, Accounts Receivable Turnover, Operating Margin, Cost of Goods Sold, Market Capitalization, and Enterprise Value. The Similarity to Ideal-TOPSIS with Distance Entropy (SITDE) method was applied to objectively determine the weights of the criteria, while the Rank Aggregation with Weighted Entropy and Ideal Closeness (RAWEC) method was employed to rank the alternatives. The results of the study, in 2021, during the post-pandemic recovery, companies’ ROCE and Accounts Receivable Turnover were the most influential criteria. Tobin's Q, reflecting long-term investor and market expectations, remained highly important across all years. In 2022 and 2023, Enterprise Value and Market Capitalization emerged as key factors, highlighting the impact of company size and investor confidence on financial performance.