Abstract This study aimed to identify genetic markers for body weight in adult male Dongfeng sika deer (Cervus nippon) using a genome-wide association study (GWAS). A cohort of 266 healthy, five-year-old stags was phenotyped and genotyped via whole-genome resequencing. Population structure was assessed, and a mixed linear model (MLM) was employed for association testing, followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of candidate genes.