Tropical forest degradation, particularly within protected areas (PAs), represents an insidious form of land degradation that undermines ecosystem resilience, biodiversity, and carbon storage. Yet, degradation dynamics along PA boundaries remain poorly quantified at fine spatial scales. This study provides a spatially explicit assessment of edge-driven forest degradation in three ecologically significant PAs in Bangladesh—Bhawal National Park (BNP), Teknaf Wildlife Sanctuary (TWS), and Rema-Kalenga Wildlife Sanctuary (RKWS)—over a 23-year period (2001–2023). Leveraging the Hansen Global Forest Change dataset at 30 m resolution, we quantified tree cover loss across concentric buffer zones (0–500 m, 500–1000 m, and 1000–1500 m) and stratified results by canopy density to identify structurally vulnerable forest patches. Results reveal that degradation is spatially concentrated along PA edges: RKWS and TWS experienced the highest losses in the 0–500 m zone (12.4 ha/ha and 11.7 ha/ha, respectively). High-canopy forests (>75% cover) were disproportionately affected, contributing to 85% of total loss in RKWS. BNP exhibited a more diffuse degradation pattern, while TWS and RKWS showed intensified edge fragmentation. These findings expose a critical governance blind spot: legal protection does not ensure ecological integrity without spatially informed management. By integrating fine-scale remote sensing with landscape metrics, this study introduces a transferable methodology for identifying degradation-prone zones and prioritizing spatially targeted restoration. The approach offers broader utility for sustainable land management, particularly in tropical nations balancing conservation mandates with socio-demographic pressures. Insights are directly relevant to achieving ecosystem restoration targets under the Bonn Challenge and the UN Decade on Ecosystem Restoration.