Purpose: There are inconsistent research findings regarding the impact of rurality on adolescent alcohol, tobacco, and illicit substance use. Therefore, the current study reports on the effect of rurality on alcohol, tobacco, and illicit drug use among adolescents in 2 state representative samples in 2 countries, Washington State (WA) in the United States and Victoria (VIC) in Australia. Participants: The International Youth Development Study (IYDS) recruited representative samples of students from Grade 7 (aged 12 to 13 years) and Grade 9 (aged 14 to 15) in both states. A total of 3,729 students responded to questions about alcohol, tobacco, cannabis, and other illicit substance use (n[subscript VIC] = 1,852; n[subscript WA] = 1,877). In each state, males and females were equally represented and ages ranged from 12 to 15 years. Methods: Data were analyzed to compare lifetime and current (past 30 days) substance use for students located in census areas classified as urban, large or small town, and rural. Findings were adjusted for school clustering and weighted to compare prevalence at median age 14 years. Findings: Rates of lifetime and current alcohol, tobacco, and cannabis use were significantly higher in rural compared to urban students in both states (odds ratio for current substance use = 1.31). Conclusions: In both Washington State and Victoria, early adolescent rural students use substances more frequently than their urban counterparts. Future studies should examine factors that place rural adolescents at risk for alcohol, tobacco, and illicit drug use.