<p>Green-synthesized carbon dots (G-CDs) have emerged as promising biocompatible and sustainable nanocarriers for drug delivery applications. Produced from renewable natural and waste-derived precursors, these nanomaterials exhibit ultrasmall size, abundant surface functional groups, high aqueous dispersibility, and intrinsic photoluminescence, enabling efficient drug loading, controlled release, and real-time bioimaging capabilities. Recent advances have demonstrated their versatility as functional drug delivery platforms through tunable surface engineering, enhanced loading efficiency, and stimuli-responsive release behavior. In addition, targeting strategies and theranostic functionalities have been increasingly explored, supported by representative in vitro investigations that highlight their multifunctional performance. Despite these advances, clinical translation remains limited due to precursor-dependent variability, lack of standardized characterization methods, insufficient long-term safety data, and scalability constraints in large-scale production. This review critically evaluates the green-synthesized carbon dots as sustainable multifunctional nanocarriers for drug delivery and theranostic applications, with emphasis on synthesis strategies, drug loading, stimuli-responsive release, targeting approaches, and translational challenges.</p>