Staff at campus-based counselling and disability centres in 15 of Ontario's 24 community colleges completed 3,536 surveys on 1,964 individual students querying the presence of mental illness and academic challenges as reported by students accessing these services. Survey data were analyzed to determine prevalence rates of mental disorders and investigate for the presence of a relationship between specific mental illnesses and any associated academic impacts. More than half of these students had diagnoses with mood and anxiety disorders being the most common individual and comorbid diagnoses. The academic challenges reported by students with mental illnesses occurred in particular patterns relative to specific diagnoses; alertness/attention challenges were associated with mood disorders, whereas memory/executive function problems were linked to anxiety disorders. Implications for training and service practices of counselling and disability staff are reviewed as are future research directions for accommodating the academic needs of students with mental illnesses.