Previous research suggests that the effect of therapist factors on patient outcomes is significant. Yet, to date, no reviews have explored the potential effects of therapist characteristics on treatment outcomes for children and youth with posttraumatic stress disorder (PTSD). This systematic review and meta-analysis aimed to summarize the professional characteristics of trial therapists delivering trauma-focused cognitive behavioral interventions (TF-CBT) for child PTSD in clinical trials and understand the association between treatment efficacy and therapist factors. Systematic searches for randomized controlled trials (RCTs) published through November 3, 2020, were conducted; 40 RCTs were included in the full review. PTSD treatment outcome data were extracted from each publication along with any available data regarding trial therapists. Subgroup analyses were conducted to compare the outcomes of interventions conducted by different types of therapists. All therapist groups yielded significant effects for TF-CBT relative to active and passive control conditions, with the largest effect size, Hedges’ g = −1.11, for RCTs that used clinical psychologists and psychiatrists. A significant moderating effect was found when comparing the treatment outcomes of clinical psychologists and psychiatrists versus other professionals, p = .044; however, this effect was no longer apparent when only studies with an active control arm were included. Further moderator analyses demonstrated no significant differences regarding therapists’ educational and professional backgrounds and PTSD treatment outcomes. The current RCT evidence for TF-CBT for children and youth with PTSD does not suggest that therapist educational or professional background influences treatment efficacy. Limitations and implications for future research are discussed.