There is a dearth of research examining repeat human trafficking victimization among children involved with the child welfare system (i.e., single system involvement) and children involved with both the child welfare and juvenile justice systems (i.e., dual system involvement). This study uses longitudinal statewide linked administrative data from the Florida Department of Children and Families (DCF) and Florida Department of Juvenile Justice (DJJ) to investigate both initial and subsequent verified human trafficking allegations among single and dual system-involved children. We conducted logistic regression models to identify youth characteristics, prior DCF experiences, and prior DJJ experiences that predict initial and subsequent trafficking victimization. We also conducted survival analysis to identify time until human trafficking victimization and revictimization. Prior maltreatment, placement history, missing child events, referral without adjudication, community supervision, and residential facility placement predict initial trafficking victimization. These same indicators predict revictimization, except for prior placement history, residential facility commitment, prior physical abuse and prior sexual abuse. Approximately 1 in 5 child victims experience trafficking revictimization; the median time between initial and subsequent revictimization is about 6 months. This research has implications for policy and practice among system-involved children at greatest risk for human trafficking revictimization.