Determining the effects of chemicals used in agricultural pest control on non-target organisms such as parasitoids is crucial for biological control programs. The pupal endoparasitoid wasp Pimpla turionellae (Hymenoptera: Ichneumonidae) is an important biological control agent that relies on natural hosts, such as the greater wax moth Galleria mellonella (Lepidoptera: Pyralidae), to complete its development. This study aimed to evaluate the in vivo and in silico impacts of the antifungal agent terbinafine (TRB) on the oxidative stress markers and detoxification enzymes of adult P. turionellae. Host G. mellonella larvae were reared on artificial diets containing varying concentrations of TRB (0.001%, 0.01%, 0.1%, and 1%) until they reached the pupal stage, after which they were exposed to parasitism by P. turionellae. The results showed that the highest TRB concentration caused a statistically significant increase in PCO content and a significant decrease in cytochrome P450 monooxygenase (CYP450) activity in adult parasitoids. Conversely, high TRB concentrations (0.1% and 1%) induced a significant increase in glutathione S-transferase (GST) activity. To support these findings, using a publicly available RNA-seq dataset, a de novo transcriptome assembly was performed to predict candidate P. turionellae CYP450 and GST structures for molecular docking. TRB displayed strong binding affinities toward both CYP450 (-8.19 kcal/mol) and GST (-7.75 kcal/mol). In conclusion, TRB exposure via the host affects the oxidative status and detoxification enzymes of P. turionellae. However, the overall in vivo and in silico findings have strengthened the possibility of TRB being a suitable candidate for use in pest control.