Vibrio is a genus of bacteria, included in the gamma subgroup of the Proteobacteria. Some are associated with diarrheal disease and other symptoms. Species of Vibrio include:

• Vibrio cholerae, the agent that causes cholera
• Vibrio vulnificus, associated with infections after eating seafood
• Vibrio parahaemolyticus
• Vibrio harveyi and Vibrio fischeri, symbiotes that live in marine animals and bioluminesce through the mechanism of quorum sensing. Also found in planktonic and parasitic forms.