<p><i>Spodoptera litura</i> is one of Asia’s most destructive agricultural pests, inflicting substantial damage on more than 300 plant species, including major crops such as soybean, cotton, and tobacco. To investigate its population structure and dispersal patterns across China, we analyzed mitochondrial cytochrome oxidase subunit 1 (COI) gene sequences from 41 geographically diverse populations. This study constitutes the most extensive genetic assessment of <i>S. litura</i> across China’s principal agroecological regions to date. Our analyses revealed (1) high haplotype diversity (<i>H</i>d = 0.614) and low nucleotide diversity (<i>π</i> = 0.00138), indicative of post-bottleneck population expansion; (2) 24 distinct haplotypes, with Hap1 and Hap3 identified as ancestral; (3) low genetic differentiation (<i>F</i>_st &lt; 0.05 in 53.41% of pairwise comparisons; analysis of molecular variance (AMOVA) showing 90.13% variation within-population); and (4) absence of isolation-by-distance (Mantel test r = 0.0387, <i>p</i> = 0.27), strongly supporting wind-assisted long-distance migration as a principal dispersal strategy. Neutrality tests and mismatch distribution analyses corroborated recent expansion events, while the haplotype network exhibited star-like configurations typical of demographic growth. Collectively, these findings offer critical insights into the metapopulation dynamics of <i>S. litura</i>, illustrating how its migratory capacity sustains genetic connectivity across China's heterogeneous landscapes. Our results provide a genetic foundation for developing region-specific surveillance protocols and predictive outbreak models under shifting climate conditions, while also informing the implementation of precision-targeted integrated pest management strategies.</p>