<p>The rapid emergence and global spread of antimicrobial resistance (AMR) have become a major public health challenge, making an urgent need for innovative antimicrobial strategies beyond conventional antibiotics. Among the various nanomaterials explored, gold nanoparticles (AuNPs) have attracted considerable attention because of their unique physicochemical properties, high surface-area-to-volume ratio, tunable surface chemistry, excellent biocompatibility, and ease of functionalization. These characteristics enable AuNPs to interact effectively with microbial cells and enhance the efficacy of antimicrobial agents. This review comprehensively summarizes recent advances (2022–2026) in the development and biomedical applications of AuNP-based antimicrobial agents against pathogenic bacteria. Unlike previous reviews that broadly discuss the biological or biomedical applications of AuNPs, the present review specifically focuses on their antimicrobial potential, recent progress, and current research trends. Particular emphasis is placed on the synthesis and surface modification of AuNPs, strategies for enhancing antibacterial activity, and the mechanisms underlying their antimicrobial effects, including membrane disruption, oxidative stress induction, biofilm inhibition, and interference with essential cellular processes. Furthermore, the review critically discusses the advantages and current limitations of AuNP-based antimicrobial systems, identifies existing research gaps, and outlines future directions for their translation into clinically relevant antimicrobial therapies. This review aims to provide a valuable and up-to-date resource for researchers developing next-generation nanomaterial-based antibacterial agents.</p>