The psychological sense of community is an important aspect of community life; yet, it remains largely unexamined among individuals with serious mental illness (SMI). Sense of community represents the strength of bonding among community members; and this social phenomenon likely impacts the process by which individuals with SMI integrate into community life. The current study examined sense of community (SOC) for individuals with SMI by assessing the relationships between neighborhood experiences, unique factors related to SMI (e.g., mental illness diagnosis), and sense of community in the neighborhood. Participants were 402 residents of supported housing programs who used mental health services in South Carolina. Hierarchical linear regression was utilized to determine which components of community life helped to explain variability in sense of community. In total, 214 participants reported that it is very important for them to feel a sense of community in their neighborhoods. Neighbor relations, neighborhood safety, neighborhood satisfaction, neighborhood tolerance for mental illness, and housing site type emerged as significant explanatory variables of sense of community. These findings have implications for interventions aimed at enhancing SOC and community integration for individuals with SMI.