Nebraska public health officials investigated an outbreak of norovirus occurring among people who attended events over a three week period at an event center. Overall, 18/25 (72%) employees and 324/1383 (23.4%) attendees from 9 of 10 events completed questionnaires. Investigators identified 159 cases; 3 were confirmed genogroup II. After the events held between October 27 and November 18, 2017, the event center attempted decontamination but failed to exclude ill food handlers. After the event center contracted professional cleaning services and agreed to exclude ill food handlers, the outbreaks ended.