The discovery of environmentally compatible antipathogenic molecules is increasingly important for sustainable crop protection. Computational chemistry and artificial intelligence (AI) provide powerful frameworks for accelerating the identification and mechanistic evaluation of bioactive molecules derived from plants and beneficial microorganisms. This review critically examines computational strategies for discovering antifungal, antibacterial, anti‐oomycete, antiviral, and nematicidal molecules, encompassing molecular‐target selection, protein structure prediction, binding‐site analysis, ligand preparation, virtual screening, molecular docking, molecular dynamics simulations, free‐energy calculations, and AI/machine‐learning‐assisted approaches. Particular attention is given to the molecular interactions of natural products and microbial metabolites with virulence‐associated proteins, effectors, signaling proteins, and essential metabolic enzymes of phytopathogens. Representative molecules, including trioxsalen, dihydroartemisinin, triamcinolone acetonide, 2,4‐di‐tert‐butylphenol, glafenine, hippuric acid, surfactin, and nicotinamide mononucleotide, illustrate the chemical diversity of emerging candidates. Current limitations associated with docking scores, protein flexibility, target validation, simulation protocols, and insufficient experimental validation are critically assessed. Integrating AI‐enabled molecular modeling with rigorous thermodynamic analyses and biological validation offers a promising route from computational screening toward chemically defined, target‐specific, and sustainable crop‐protection agents.