Itis may refer to:
Healthcare Inflammation Postprandial somnolence (colloquially "the itis"), a state of drowsiness or lassitude following a meal
Information systems Integrated Taxonomic Information System, a partnership designed to provide consistent and reliable information on the taxonomy of biological species Integrated Transport Information System, a traffic management system in Klang Valley, Malaysia
Places Itis (Swedish name of Iitti), a municipality in Päijänne Tavastia, Finland
Other uses Itis shopping centre, a shopping centre in the district of Itäkeskus in East Helsinki, Finland "The Itis" (The Boondocks), the tenth episode of the Adult Swim animated television series, The Boondocks