Classifications for severe juvenile offenders and ones that include mental health needs are lacking. Thus, in this study, adolescent male offenders (N = 652) committed to a residential facility were clustered on personality and clinical scales of the Millon Adolescent Clinical Inventory (Millon, 1993) into 5 groups (including 4 found in other typologies). As expected, the impulsive/reactive and psychopathy groups had more severe criminal histories and the impulsive/reactive and anxious/inhibited groups had increased suicidal behaviors and poor psychosocial functioning. The impulsive/reactive group showed expected verbal deficits. The unremarkable group lacked discernable personality/clinical problems and was unremarkable on dependent variables. A conforming group emerged that may be unique to severe juvenile offender populations. Future studies should examine institutional adjustment and outcomes among the identified groups.