Hoplolaimus magnistylus n. sp. is described and illustrated. It was found in soil around roots of soybean in Arkansas and Mississippi. It is similar to H. galeatus and H. concaudajuvencus. It differs from H. galeatus in all stages primarily by possession of a longer stylet. It differs from H. concaudajuvencus by the possession of rounded tails in second-stage juveniles vs. conically pointed tails with acute termini, having fewer subdivisions in female basal lip annules, and the greater distance from female anterior end to posterior end of esophageal lobes. Morphometrics and descriptions of second-, third-, and fourth-stage juveniles are given. A paratype female of H. sheri was examined and found to have six esophageal gland nuclei.