BackgroundTransition readiness, or skills and preparation for navigating adult health care, is an important factor in the successful transition from child and adolescent mental health services (CAMHS) to adult care; however, predictors of transition readiness are not fully understood. One factor which may impact transition readiness among youth accessing CAMHS is the presence of a co‐occurring physical health condition; however, this has not been previously examined. Within a cohort of youth receiving CAMHS, the objective of this study was to understand if there is an association between co‐occurring physical health conditions and transition readiness and if this relationship is impacted by severity of mental health symptoms.MethodsThis study was a secondary analysis of baseline data from the Longitudinal Youth in Transition Study, including 237 16‐ to 18‐year‐old youth accessing outpatient CAMHS from four different clinical sites. Participants completed self‐report measures on mental health symptoms, functioning, service use, transition readiness, and physical health conditions. Multiple linear regression models were used to measure the association between the presence of health conditions and transition readiness scores as well as determine if there was an interaction between mental health symptoms and physical health conditions to predict transition readiness.ResultsCo‐occurring physical conditions were reported by 41% of youth and were associated with greater overall transition readiness. There was no interaction between mental health symptom severity and co‐occurring physical conditions, though attention problems were independently associated with lower transition readiness scores.ConclusionsYouth accessing CAMHS who have a co‐occurring physical condition have overall greater transition readiness than youth without a co‐occurring condition. Further research should explore the role of frequency and types of healthcare encounters in transition readiness for transition age youth needing ongoing mental health care to better understand how to support self‐management and care navigation skill development.