Microplastics (MPs) are small plastic particles that are present in the environment and have been recognized as a significant threat to environmental sustainability. Microbial biofilms, which are complex communities of microorganisms, are known to play a crucial role in the biodegradation of microplastics. These MPs provide a surface for adhesion of antibiotic-resistant bacteria, antimicrobial-resistant genes, antibiotics, MGEs, toxins, and other chemical pollutants. This chapter gives an overview of the associations between MPs, microbial biofilms, and the spread of antibiotic resistance genes (ARGs), with a focus on their implications for environmental sustainability and human health. MPs act as microbial colonization vectors, encouraging the creation of biofilms that enable the transmission of ARGs and worsening the spread of antibiotic resistance. The implications of these interactions for environmental sustainability and human health are also discussed. The chapter also highlights concerns about the direct impact of MPs on human health. Overall, this book chapter provides a valuable contribution to the literature on microplastic pollution and MP-mediated transmission of antimicrobial resistance genes and its impacts on ecosystem sustainability.