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Copper (Cu) is an essential metal for plants. However, its excess in soil can adversely affect plant metabolism. The current study evaluated the effects of gibberellic acid (GA₃) foliar applications on the performance of pea plants grown either in Cu-contaminated (Cu+) and non-contaminated (Cu−) soil. GA₃ was sprayed (0, 10, 50, and 100 mg·L⁻¹) on 15-days-old plants. The results showed that the increasing concentration of GA₃ buffered the phytotoxic effects of Cu and enhanced plant growth, photosynthesis, and leaf chlorophyll content. Foliar-sprayed GA₃ up to 100 mg·L⁻¹ alleviated the oxidative stress, as inferred from the lower concentrations of MDA and H₂O₂ (33.3 µmol·g⁻¹ and 182 µmol·g⁻¹, respectively), and boosted the activity of superoxide dismutase (64.4 U·g⁻¹·FW), peroxidase (122.7 U·g⁻¹·FW), and catalase (226.3 U·g⁻¹·FW). Interestingly, GA₃ promoted Cu accumulation in different plant parts when compared to untreated plants, likely due to increased photosynthetic and transpiration rates. Overall, foliar application of GA₃ promoted phytoextraction of Cu and alleviated the oxidative stress in pea plants grown in Cu+ soil.