Little information is available on the efficacy of Group 4 herbicides for glyphosate-resistant (GR) horseweed management in soybean. Five field research trials were established in growers’ fields from 2020 to 2021 to determine GR horseweed control with Group 4 herbicides applied pre-plant (PP) alone and in a mixture. There was minimal soybean injury (≤4%) with herbicides evaluated. Dicamba, 2,4-D, or halauxifen-methyl applied PP, controlled GR horseweed 92-96, 73-76, and 85-89%, respectively. The mixtures of dicamba + 2,4-D, dicamba + halauxifen-methyl, and dicamba + 2,4-D + halauxifen-methyl gave 97-99% control of GR horseweed, which were similar to dicamba applied alone. The mixture of 2,4-D + halauxifen-methyl gave 93-94% control of GR horseweed. Dicamba + saflufenacil controlled GR horseweed at 98%. Dicamba alone, dicamba + 2,4-D ester, dicamba + halauxifen-methyl, and dicamba + 2,4-D ester + halauxifen-methyl decreased GR horseweed density 97, 99, 99, and 98%, respectively, which were comparable to a 98% density reduction with dicamba + saflufenacil. Other herbicide treatments had no effect on GR horseweed density. Dicamba, 2,4-D, and halauxifen-methyl applied PP, decreased GR horseweed dry biomass by 99, 76, and 72%, respectively. The mixtures of dicamba + 2,4-D, dicamba + halauxifen-methyl, and dicamba + 2,4-D + halauxifen-methyl decreased GR horseweed dry biomass by 99-100%, which was comparable to a 99% dry biomass reduction with dicamba + saflufenacil. The mixture of 2,4-D + halauxifen-methyl decreased GR horseweed dry biomass by 94%. Soybean yield was decreased by 61% when GR horseweed was left uncontrolled. Results show that Group 4 herbicides that include dicamba applied PP can be very effective in managing GR horseweed in soybean.