Plant–bacterial interactions play a pivotal role in agriculture, influencing both pathogenic infections and beneficial symbioses. A key regulatory mechanism in these interactions is cell-to-cell communication system for bacteria to coordinate gene expression and respond to population density. Quorum sensing (QS) relies on small signaling molecules, such as acyl-homoserine lactones (AHLs), autoinducer peptides (AIPs), and diffusible signal factors (DSFs), which regulate virulence, biofilm formation, and mutualistic behaviors. In pathogenic bacteria, QS controls the expression of virulence factors, host invasion, and biofilm development, enhancing bacterial survival and resistance to plant defenses. Conversely, in beneficial bacteria, QS facilitates symbiotic colonization, nutrient exchange, and stress tolerance, promoting plant growth and health. Recent studies highlight the dual role of plant-derived compounds, such as salicylic acid (SA) and flavonoids, in modulating QS pathways either suppressing pathogenic QS or enhancing beneficial bacterial communication. Additionally, quorum quenching (QQ), the disruption of QS signals, has emerged as a sustainable strategy to combat bacterial infections without promoting antibiotic resistance. Understanding the molecular mechanisms of QS in plant–microbe interactions provide insights into developing novel biocontrol agents and engineering beneficial microbial consortia for agriculture. This review synthesizes current knowledge on QS-mediated plant–bacterial interactions, emphasizing its implications for disease management, crop productivity, and sustainable farming practices. By exploiting QS mechanisms, future research can pave the way for eco-friendly alternatives to chemical pesticides, fostering resilient plant-microbe ecosystems.