Despite extensive theory and research on the geography of crime, few studies have examined the geography of commercial sex and sex trafficking through a criminological lens. As such, this study explores how social disorganization and routine activities help explain the geography of commercial sex venues, specifically illicit massage businesses (IMBs) that host commercial sex. Because IMBs have also been linked to sex trafficking, understanding which environmental contexts are conducive to their presence may also help identify sex trafficking premises. Findings from hierarchical logistic regression models indicate that both theories point to significant correlates of IMB placement in census tracts and cities, yet neither theory provides a sufficient explanation alone. Implications for future research and policy will be discussed.