Derek Nelsen

Derek Nelsen is a Sioux Falls attorney with Fuller Williamson Nelson Preheim whose practice is devoted to litigation. Derek focuses on insurance-based cases, personal injury matters, and commercial disputes. He tries jury cases across South Dakota, argues before the South Dakota Supreme Court, and appears regularly in federal court. His work is centered on contested matters that require case strategy, evidence development, motion practice, and effective trial advocacy.

Derek graduated with distinction from the University of Nebraska, Lincoln and then attended the University of South Dakota School of Law. In law school, he served simultaneously as a Law Review Editor and Moot Court Board Member. He graduated as a Sterling Honors Graduate and received the Law School’s Gavel Award. Those academic and advocacy experiences provided strong preparation for a career focused entirely on litigation.

After law school, Derek clerked for Justice Judith Meierhenry of the South Dakota Supreme Court. He later developed a comprehensive trial practice involving insurance disputes, serious personal injury claims, and commercial cases. Derek’s work includes jury trials, appellate arguments, and federal-court litigation, requiring him to manage factual records, expert issues, dispositive motions, and courtroom presentation while keeping the client’s practical goals in view.

Derek Nelsen holds an AV-Preeminent peer rating for legal ability and professional ethics. Derek’s career combines appellate clerkship experience with a litigation-only practice and frequent work in South Dakota courts. He is known for a client-centered approach built around listening, preparation, and sustained advocacy. His experience is particularly relevant when claims involve insurers, substantial damages, business disputes, or the possibility of trial and appeal.

Law Office Affiliations

• Attorney, Fuller, Williamson, Nelsen & Preheim, LLP
• Member, State Bar of South Dakota

Licensed State

• South Dakota

Awards & Badges