Toronto Public Health has confirmed that norovirus is what caused at least two students to become ill at Humber College last week.
Norovirus is highly contagious and causes vomiting and diarrhea.
Dozens of students fell ill at the north campus. Officials say that about 75 per cent of the students report feeling better.
Humber's Dean of Students, Jen McMillan, told reporters that the source of the illness has not yet been determined.
She is asking students to remain vigilant and frequently wash their hands. The school has taken precautions including increasing cleaning schedules and thrown out some of the food.