Background: Post-traumatic growth (PTG) refers to positive psychological changes resulting from the struggle with highly challenging or traumatic life events. Psychosocial interventions have demonstrated efficacy in promoting psychological well-being in the aftermath of traumatic experiences. Cognitive Behavioral Therapy (CBT) is among the most extensively studied such interventions, aligning with the PTG model’s prerequisites for growth. Objective: The aim of this systematic review was to assess the efficacy of CBT and CBT-based interventions in promoting PTG. Methods: A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, searching PubMed, Scopus, and Google Scholar databases from inception to December 2024. Eligibility criteria included: (a) the inclusion of a CBT or CBT-based intervention, (b) measurement of PTG using the Post-Traumatic Growth Inventory (PTGI), (c) study participants having experienced traumatic life events, and (d) articles written in English. Risk of bias was assessed independently by two reviewers. Due to the heterogeneity of included studies, a qualitative narrative synthesis approach was adopted. Risk of bias was assessed using the RoB-2 tool for RCTs, ROBINS-1 for quasi-experimental studies and Newcastle–Ottawa scale for cohort studies. Certainty of evidence, assessed using the GRADE framework, is considered low. Results: A total of 19 studies were included (13 randomized controlled trials, 3 quasi-experimental, and 3 longitudinal studies). While traditional CBT produced mixed results in fostering PTG, CBT-based therapeutic protocols—particularly those explicitly designed to target PTG or incorporating structured cognitive–emotional techniques—demonstrated more consistent benefits. Limitations of the included studies include measurement of PTG as a secondary outcome, small sample sizes, and the presence of confounding variables. Conclusions: Further high-quality, multicenter randomized controlled trials with standardized protocols are needed to clarify the role of CBT in promoting growth after trauma.