This paper examines how Türkiye’s registered population of Syrians under temporary protection (SUTP) evolved nationally and across provinces after the fall of the Assad regime in December 2024. Using monthly administrative data for all 81 provinces from January 2024 through June 2026, we treat the October–November 2024 drop associated with nationwide address verification and record cleaning separately from subsequent changes. The analysis combines an interrupted time trend, an adjusted pre-event counterfactual, and province-level analysis of geographic heterogeneity. The SUTP population was already declining before December 2024, but the post-event trend became substantially steeper. By June 2026, the registered population stood about 509,000 below the adjusted pre-event trajectory. The decline intensified in the second half of 2025 before moderating in early 2026. Declines occurred in 77 provinces, with absolute reductions concentrated in major hosting provinces. Changes relative to pre-event trends were generally more negative farther from the Syrian border, a relationship that remains negative across robustness checks but weakens under population weighting.