Pathogenic bacteria from hospital effluents often persist in wastewater even after treatment, reaching discharge sites and recreational waters where they act as reservoirs for mobile antibiotic resistance genes (ARGs). These genes circulate within microbial communities, amplifying antimicrobial resistance (AMR). This study investigates AMR transmission from hospitals to wastewater systems in Réunion Island. Réunion Island, a French overseas territory in the Indian Ocean, faces growing AMR challenges being a travel and healthcare hub across diverse socioeconomic backgrounds, making it a suitable setting to study mechanisms of AMR dissemination. Here we explored AMR dissemination by linking hospital wastewater metagenomic data through metagenome-assembled genomes (MAGs) and plasmids to clinical isolates. Using consolidated bins from BASALT and PacBio HiFi MAG pipeline with metaMDBG as the assembler, we recovered 904 MAGs representing 264 unique species. PlasX was employed to predict plasmids both within MAGs and at the contig level. Plasmids, over MAGs, were identified as better suited to link clinical and environmental datasets. Clustering plasmids sharing ≥90% sequence identity and coverage yielded 341 plasmid systems, 39 of which carried ARGs. Two large systems, PS327 and PS328, contained plasmids from both clinical and wastewater sources and encoded clinically relevant beta-lactamases, including blaNDM-1 on the PS327 backbone and blaOXA-181 and blaCMY-6 across both systems. blaOXA-17 and blaOXA-4 appeared predominantly in metagenomic datasets, while blaTEM-1B, blaDHA-1, blaDHA-7, and blaDHA-24 were largely within clinical isolates. Together, these findings reveal shared plasmid systems that mediate ARG flow from clinical settings into wastewater, highlighting critical pathways of AMR spread.