This study evaluated the effects of a high-concentration soy pulp (HSP) diet on pig production performance and carcass traits under commercial farming conditions. Data were collected from a pig farm in Jeju, Korea, between 2019 and 2024. From 2019 to 2021, pigs were fed a control diet containing 2.3% soy pulp, and from 2022 to 2024, the proportion of soy pulp was increased by 254% (HSP, 21.9%). We evaluated production performance indicators including shipment date, feed cost per kilogram of weight gain, feed conversion ratio, carcass weight, carcass yield, and proportion of high-grade carcasses. The feed cost per kilogram remained constant under both diet conditions; however, pigs fed an HSP diet reached market weight significantly earlier than those on the control diet and the feed conversion ratio, carcass weight, and proportion of high-grade carcasses were significantly improved. The carcass yield percentage was non-significantly higher for pigs fed the HSP diet than for those fed the control diet. These findings suggest that providing HSP feed to grow–finish pigs enhance growth performance, improves carcass quality, and shortens the production period, indirectly reducing feed costs. Further studies should explore the long-term economic impacts and potential interactions of HSP with gut health and nutrient digestibility.