Lifestyle factors serve an important determinant of health and are critical to youths’ psychosocial development. This cross-sectional survey study aimed to assess the associations between lifestyle practices and mental health and substance use among a sample of 152 Chinese-Canadian youth in the Greater Toronto Area. Findings indicated that youths’ sedentary behaviors are linked to increased depressed mood, stress, and suicidal ideation. Moreover, a lack of healthy eating habits is associated with increased substance use. The use of a buddy program, installation of peer counseling, and an implementation of a holistic health policy may help promote healthy living for Chinese-Canadian youth.