Oral language competence is a basic prerequisite for functional and prosocial development across the lifespan, but has been inadequately investigated in young people in whom behaviour disturbance is the dominant concern. Previous work in Australia and overseas has shown that young offenders serving community-based orders are at high-risk for undetected but clinically significant oral language (everyday talking and listening) difficulties. However this phenomenon has received little attention in incarcerated samples, and links with offending severity, mental health, and other markers of early risk (e.g., a history of early Out of Home Care placement) have not been systemically examined. A cross-sectional examination of one hundred (100) young offenders (mean age 19.03 years, SD = .85) completing custodial sentences in Victoria, Australia was carried out. Participants were assessed on a range of standardised oral language, IQ, mental health and offending-severity measures. Language measures were selected for their sensitivity to a range of everyday linguistic competencies, such as listening comprehension, the ability to define words, and to understanding of everyday idioms and other forms of non-literal language. Language impairment (LI) was operationally defined as performance below two standard deviations below the mean on two standardised language measures (the CELF4 and the TLC-E). Forty-six percent of participants were classified as language impaired (LI), using this definition. When the subgroup with high offending scores was compared with those with (relatively) lower offending scores, significant differences on a range of language measures were identified. A range of early risk indicators (such as placement in Out of Home Care) was also examined with respect to language impairment in this high-risk group. Unidentified oral language impairments are over-represented in young men in the justice system, and may serve to further marginalise this already disadvantaged group. Implications for early intervention, passage through the justice system, and receipt of therapeutic services are dis.cussed. Young offenders should be routinely screened for Ll and interventions should be tailored accordingly.