California Institute of the Arts, or CalArts, has been closed since last Friday after several people became very sick with flu-like symptoms.
The Los Angeles County Public Health Department says norovirus is suspected, but an official cause for the sickness has not yet been determined.
Crews have been cleaning university buildings, including the common areas, offices and classrooms, and all public areas and restrooms have been cleaned and sanitized.
Classes are expected to resume Tuesday.
CORRECTION: It was earlier reported that the sickness was spread through cafeteria food, but health officials have not yet determined the cause of the sickness.