Persons with mental illness often have low self-esteem, a lack of self-expression, and poor social skills. This study used a quasi-experimental two-group pre-test-post-test design to investigate the effects of food art therapy on the self-esteem, self-expression, and social skills of persons with mental illness attending community rehabilitation facilities. The authors recruited persons with mental illness aged 18 years or older attending three community rehabilitation facilities. Participants in two rehabilitation facilities participated in food art therapy (experimental groups 1 and 2; n = 15 for each group), and participants in the third rehabilitation facility participated in regular programs of the facility (control group, n = 30). Participants in the experimental groups attended a total of eight sessions of food art therapy twice per week for four weeks. The Korean versions of the Rosenberg self-esteem scale, self-expression scale, and social skill rating system were administered at pre- and post-test in both the experimental and control groups. The self-esteem, self-expression, and social skills of the experimental group improved significantly compared to the control group. The findings suggested that food art therapy would be an excellent psychosocial intervention to help persons with mental illness to rehabilitate in the community.