<p>Global protein demand has increased, driven by population growth and climate change, which have widely impacted weather conditions and crop production. Soybeans are an affordable protein source for both humans and animals. However, achieving high protein and grain yields (GYs) requires not only maximizing the absorption capacity beyond biological nitrogen (N) fixation (BNF) for N supply but also closing yield gaps. Additionally, nickel (Ni) is essential for FBN and N metabolism. Based on these findings, applying foliar N and N+Ni during periods of high N demand can increase soybean performance, which is vital for maintaining yields. This study evaluated whether foliar fertilization with N and N+Ni enhances soybean GY, yield components, N nutrition, and grain protein and oil contents. For each commercial soybean variety, separate field experiments were conducted in 2019/20 and 2020/21 at Londrina, PR, Brazil. The experimental design was randomized blocks with three treatments and eight repetitions. Foliar fertilization with N and N+Ni increased GY for BRS 399 RR, but only in the first season, compared with the control. Conversely, the GY of cultivar BRS 284 was not significantly affected by N or N+Ni in either season. However, the N concentration in the leaves increased in both seasons with the N and N+Ni treatments in cultivar BRS 284 relative to the control. For the BRS 399 RR, the N concentration increased with both treatments only in the first season, leading to increases in the seed protein yield of 15.1% and 12.5%, respectively. The highest grain N uptake values, 347.5 and 359.1 kg ha^-1, were recorded for BRS 399 RR. Finally, the application of N and N+Ni improved the gross revenue and profitability of BRS 399 RR compared with those of the control in the first season. Foliar spraying of N and N+Ni enhances GY, protein yield, and profitability, especially when weather conditions are favorable and when a responsive cultivar is used.</p>