Globally, the contamination of aquatic bodies by improper application of pesticides, particularly fungicides, endangered aquatic life and hampered sustainable aquaculture. Exploring innovative strategies to mitigate this difficult issue as ecofriendly and cost-effective is indispensable. Herein, the potential of dietary Egyptian mallow (Malva parviflora) leaves (EML) as a powder form to mitigate the toxicological implications of metiram (MET) exposure in Oreochromis niloticus (Nile tilapia) was assessed in this attempt. The investigation featured growth, physiological, immune/antioxidant responses, splenic cytokines expression, and histopathological concepts. In light of this, fish (N = 200; 32.80 ± 0.92 g) were eventually assigned into four groups with five sets (control, EML, MET, and EML + MET) for 63 days. The control and EML groups were given basal diets that had 0 and 15 g EML/kg diet, respectively, without MET exposure. Furthermore, MET and EML + MET groups were received the identical diets as control and EML groups, respectively, and exposed to 0.38 mg/L MET. The findings highlighted a significant (P < 0.001) growth retardation (declining in weight gain and specific growth rate) and higher fish mortality (32%) by MET exposure. Also, immune impairment (lowered immunoglobulin M and complement 3) and oxidative damage (higher malondialdehyde and declined catalase and superoxide dismutase) were the outcomes of MET toxicity. In addition, the biochemical biomarkers showedsubstantial disruptions (P < 0.001) in the MET group, where creatinine, aspartate aminotransferase, and alanine aminotransferase increased. Splenic expression of immune-relevant cytokines (interleukin-10 and interferon-gamma 1) was downregulated with upregulation of apoptosis (cysteine-aspartic acid protease-3) linked gene by MET toxicity (P < 0.001). Histologically, MET significantly provoked a diverse range of aberrations in the spleen, kidney, and liver tissues. Remarkably, feeding the EML diet to the MET group decreased fish mortality (14%) and refined all metrics, while retaining the histological integrity of tissues. The conclusion of this viewpoint recommends using dietary EML (15 g/kg) to diminish the deleterious effects of MET in toxicity in Nile tilapia to sustain aquaculture.