Bisphenol A (BPA), a widely used industrial chemical, poses environmental concerns due to its persistence and potential effects on plant systems. This study examines the impact of three BPA exposure levels on parsley plants, focusing on physiological, biochemical, and metabolomic responses. BPA exposure significantly shaped the plant's defense mechanisms, mainly through increased phenolic (up to 16.81%) and flavonoid (up to 37.94%) accumulation compared to the control group, which, in turn, enhanced antioxidant activity [up to 34% in 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 51% in cupric reducing antioxidant capacity (CUPRAC)]. A moderate correlation between phenolic content and radical scavenging ability [R: 0.61 for DPPH and R: 0.44 for 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)] highlights phenolics' role in mitigating BPA-induced oxidative stress. Low BPA concentrations stimulated gas exchange and photosynthesis, while higher levels (≥3 mg/L) disrupted these processes, causing physiological damage, especially in stomatal conductance (gs) and photochemical efficiency (Fv/Fo). Metabolomic profiling revealed concentration-dependent shifts in secondary metabolism, lipid biosynthesis, and stress-response pathways. At higher BPA levels, plants elicited defense mechanisms, such as flavonoids (rhamnetin, luteolin-7-O-β-D-glucronide, and quercetin-7-O-glucoside) and anthocyanin pathways, to tackle oxidative stress, though these systems became overwhelmed. Our findings show that while parsley can initially adapt to low BPA exposure, higher concentrations compromise its physiological and metabolic balance, threatening plant health and productivity.