This paper examines regional inequality dynamics in Turkey over the 2006-2024 period using firmlevel administrative data from the Entrepreneur Information System (GBS). Drawing on 22.85 million firm-year observations across 81 provinces and 19 years, we apply sigma convergence analysis at three spatial scales: provincial (81 NUTS-3 units), regional (26 NUTS-2 units), and within-region (firm-level dispersion inside each region). Net sales and gross value added are deflated using producer price indices (base year 2006). The findings reveal a three-phase pattern: convergence during 2006-2012 (-20.8% net sales,-9.5% gross value added), near-stagnation during 2013-2019, and sharp divergence after 2020 (+32.6% net sales, +25.4% gross value added). Crisis-exclusion tests confirm that some convergence episodes partially reflect deterioration rather than genuine catch-up. Withinregion analysis identifies club convergence: firms converge inside all 26 NUTS-2 regions for net sales, yet between-region dispersion widened by 38% over the full period. No locomotive province is identified at the national level. The results suggest polarization rather than systemic convergence.