Campylobacter infection, or campylobacteriosis, is an infectious disease caused by Campylobacter bacteria. It is one of the most common causes of diarrheal illness in the United States. The Foodborne Diseases Active Surveillance Network (FoodNet) indicates that about 14 cases are diagnosed each year for every 100,000 people. Many more cases go undiagnosed or unreported.

CDC estimates Campylobacter infection affects more than 1.5 million people every year. Most cases are not part of recognized outbreaks, and more cases occur in summer than in winter.