Soybean serves as a primary global source of high-quality protein and oil, and improving its yield and quality is critical for global food security. Despite advances in gene editing and molecular breeding, the regulatory mechanisms underlying leaf senescence remain poorly understood, limiting yield gains in soybean. Building on our previous identification of SNAP1/2/3/4—a cluster of NAC transcription factors regulating nodule senescence—we reported their pivotal role in modulating aboveground agronomic traits. The knockout mutants of SNAP1/2/3/4 exhibited delayed leaf senescence and prolonged maturation period. These changes led to concurrent improvements in grain yield, seed size, and oil content. Our study reveals a dual regulatory function of SNAP1/2/3/4 in both nodule and leaf senescence and uncovers a molecular target to coordinately enhance soybean yield and quality by fine-tuning of developmental timing.