Antimicrobial resistance (AMR) remains one of the most critical global health threats of the 21st century, sustained not only by the clinical misuse of antibiotics but also by environmental contamination resulting from inadequate waste governance. The improper disposal of pharmaceutical, agricultural, and healthcare waste introduces antimicrobial residues into soil, water, and food systems, creating reservoirs where resistant microorganisms thrive and spread. This paper examines the intersection of waste management and regulatory frameworks as a cornerstone in mitigating AMR. Drawing on international guidelines, national legislation, and institutional policies, it analyzes how regulatory instruments govern antimicrobial discharge, pharmaceutical waste treatment, and environmental monitoring. Case studies illustrate both regulatory successes in high-income settings—where binding legal frameworks and advanced monitoring technologies have reduced antimicrobial effluents—and the persistent challenges in low- and middle-income countries, where weak institutional capacity, limited infrastructure, and fragmented governance undermine implementation. The discussion emphasizes the role of harmonized global standards, enforceable compliance mechanisms, and multi-sectoral collaboration across healthcare, agriculture, and environmental systems. By embedding AMR prevention within sustainable waste regulation, the paper argues that adaptive, evidence-driven, and internationally coordinated governance models are essential to curbing resistance at its ecological roots and securing long-term public health resilience.