This study identified genomic regions associated with carcass traits and primal cut yields in Hanwoo cattle using weighted single-step genome-wide association study (WssGWAS). A total of 50,227 carcass records and genomic data from 23,573 animals with 45,057 single-nucleotide polymorphisms were analyzed. Heritability estimates were 0.24 for carcass weight, 0.22 for eye muscle area, 0.31 for backfat thickness, and 0.36 for marbling score, while those for primal cut yields ranged from 0.02 to 0.26. For carcass traits, candidate genes were identified for carcass weight (XKR4 2.35%, COBL 1.26%), eye muscle area (LCORL 1.56%, TGFBR2 1.49%), backfat thickness (ATG7 1.27%, MYPN 1.33%), and marbling score (TWIST2 1.16%, BMP4 1.14%). For primal cut yields, the chromosome 6 region containing WDR1 was commonly identified across six traits and the chromosome 4 region containing CACNA2D1 across five traits; the chromosome 28 region containing SIRT1 explained the highest genetic variance (6.46%) for striploin. These pleiotropic regions are potential targets for genomic selection to improve production efficiency and carcass value in Hanwoo.