This study examined the effects of high magnesium (+Mg), manganese (+Mn), and their combination (+Mg+Mn) on purple and green basil compared to a control (-Mg-Mn). Purple basil showed increased biomass and rosmarinic acid with Mn, while green basil had varied nutrient levels. Both had high protein and low fat, with the best antioxidant activity in purple basil (+Mg) and green basil (+Mg+Mn). Nutritional profiles were analyzed with AOAC, HPLC, and GC-FID; antioxidant, antimicrobial, cytotoxic, and anti-inflammatory activities were tested on hydroethanolic extracts. Mn enrichment increased purple basil biomass and altered Ca, Mg, Mn, and Zn levels, while Mg-treated plants had higher Mg and Mn but lower Zn. Green basil showed increased Mg with high-Mg treatment and higher nutrient levels with high-Mn treatment, though Na was reduced. The +Mg+Mn treatment caused variable nutrient content in green basil. Both basil types had high protein, low fat, and varied sugar content, with palmitic acid as the major fatty acid. Purple basil had 25 phenolic compounds, with rosmarinic acid being predominant in the control treatment and high α-tocopherol and γ-tocopherol levels with +Mg. Green basil's had the most rosmarinic acid in the +Mg+Mn treatment, and it had the highest amount of α-tocopherol in the -Mg-Mn treatment and γ-tocopherol with +Mg treatment. Antioxidant activity was the highest in purple basil with +Mg (IC50 = 47 ± 4 μg/mL) treatment and green basil with +Mg+Mn (IC50 = 45 ± 1 μg/mL) treatment. Purple basil showed no anti-inflammatory activity, while green basil with -Mg-Mn effectively inhibited NO production. Both basil types had antimicrobial activity, with Staphylococcus aureus being more susceptible to purple basil and Listeria monocytogenes being more susceptible to green basil. Overall, both types of basil show significant nutritional, chemical, and bioactive potential for the food industry.