Itis may refer to
- 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
- "The Itis" (The Boondocks), the tenth episode of the Adult Swim animated television series, The Boondocks
- Itis shopping centre, a shopping centre in the district of Itäkeskus in East Helsinki, Finland
- Postprandial somnolence (colloquially "the Itis"), a state of drowsiness or lassitude following a meal