Sex trafficking of minors is a significant problem across North America, with sizeable numbers of youth being directly or indirectly manipulated into being exploited or trafficked. Identification of these youth remains difficult, in part because of a lack of knowledge about common characteristics and in part because of victims' reluctance engaging with and trusting law enforcement enough to disclose their experiences. Given that many youth are trafficked during school‐aged years, school settings may represent an ideal location to target prevention and identification efforts, especially by health‐related school professionals, whose training, professional duties, and often positive relationships with youth may make the professionals trustworthy disclosure recipients. Whether such professionals are effective, though, depends on their knowledge of who is at risk for trafficking, characteristics that distinguish trafficking from other forms of harm, and effective questioning approaches to elicit disclosures from victimized youth. To document whether this knowledge exists, we surveyed 361 school‐based professionals concerning their ability to identify trafficking and knowledge of trafficking, adolescent development, and interviewing youth. Although nearly all (97%) school professionals recognized general student risk in the vignettes, only 18% identified that risk as trafficking. Professionals who had prior experience with trafficked youth were more likely to recognize trafficking than those without such experience. Finally, professionals evidenced some general knowledge about the existence of trafficking, adolescent development, and interviewing, but demonstrated more limited knowledge in the most common characteristics of trafficked minors and nuanced aspects of best‐practice questioning approaches. Results highlight important directions for training of school‐based professionals to improve prevention and identification of a highly vulnerable and often overlooked population of victims, namely trafficked minors.