Although familial adversity is associated with poorer outcomes in childhood and adulthood, little research has looked at the influence of stability or transition between distinct familial adversity subgroups or the impact in adolescence. Using data from the 9-month, 3-, 5-, and 14-year time waves of the Millennium Cohort Study (n > 18,000), we used latent class analysis to identify distinct classes of early familial adversity (marital instability/conflict, “suboptimal” parenting, economic disadvantage, and parental mental health problems) and the impact of these adversity classes on adolescent (a) mental health (including self-harm), (b) risk taking, (c) criminality, and (d) victimization. Four profiles were identified largely differing on economic hardship, family composition, and parental conflict. Across the first three time points, 72% of the sample remained stable, with the remainder transitioning between classes. Adolescents in the higher risk groups (particularly categorized by economic hardship or high parental conflict) had poorer outcomes in adolescence. Transitioning to a higher adversity group at any time in the first 5 years was associated with poorer outcomes but was particularly pronounced when the transition occurred when the child was under 3 years. These findings demonstrate the broad consequences of early familial adversity and the need for targeted early support for at-risk families.