The impacts of dietary nutrient intakes on brain development during the early life have been investigated extensively. As walnuts have been historically considered beneficial for cognition, this study was set to determine the mechanism by which unsaponifiable matter (USM) of walnut oil enhances neurodevelopment. In human induced pluripotent stem cells (hiPSCs), and human cerebral organoids, USM facilitated the proliferation and differentiation of neural stem cells (NSCs). This was associated with the changes of expression of genes related to neurodevelopment and cognition, particularly those regulating the Wnt signaling pathway. Here, data derived from hiPSCs, human cerebral organoids clearly show that USM administration enhances neural development. These findings may provide intervention strategies for early life neural problems in the future.