Yellow jack (disambiguation)
The yellow jack is a species of offshore marine fish in the jack family. Yellow Jack or Yellow Jack fever may also refer to:

 Yellow fever, an acute viral disease. Typhoid fever, a bacterial disease. Yellow Jack (play), a 1934 American play about the search for the causes and treatment of yellow fever. Yellow Jack, a 1938 film adaptation of the play. The Yellow Jack, a yellow flag used to identify ships quarantined due to the presence of a disease.