A field experiment was conducted during the winter season of 2023–2024 to evaluate the effects of boron, mineral fertilizer, and organic fertilizer (cow manure) on the growth and yield of two faba bean (Vicia faba L.) cultivars: Spanish and Dutch. Boron was applied at four concentrations: 0, 3, 6, and 9 mg L⁻¹. Fertilizer treatments included mineral fertilizer, cow manure, and a combination of both. The experiment was carried out using a Randomized Complete Block Design (RCBD) in a factorial arrangement. The results showed that the Spanish cultivar outperformed the Dutch cultivar across all measured traits, recording mean values of 2082.62 cm² leaf area, 7.91 branches per plant, 5.33 seeds per pod, 152.71 g yield per plant, and 22.52% protein content. Among the boron treatments, the application of 9 mg L⁻¹ resulted in the highest values for all traits, with averages of 2480.91 cm² leaf area, 9.47 branches per plant, 6.03 seeds per pod, 249 g yield per plant, and 25.85% protein content. Regarding fertilizer treatments, the combined application of mineral fertilizer and cow manure produced superior results in all parameters, achieving mean values of 2143.64 cm² leaf area, 8.50 branches per plant, 5.64 seeds per pod, 181.16 g yield per plant, and 22.80% protein content. A significant three-way interaction (Cultivar × Boron × Fertilizer) was detected for all measured traits. The highest performance was recorded in the Spanish cultivar treated with 9 mg L⁻¹ boron and the combined application of mineral fertilizer and cow manure, achieving 2853.70 cm² leaf area, 12.10 branches per plant, 7.10 seeds per pod, 317.33 g yield per plant, and 28.56% protein content.