Abstract: Introduction: Canadian Armed Forces (CAF) Service members (SMs) experience higher rates of mild traumatic brain injuries (mTBIs) and psychosocial risk factors such as mental health diagnoses, sleep disturbances, alcohol consumption, and post-concussion symptoms than Canadian civilians. Associated challenges with executive cognitive functioning (ECF) can significantly impede their performance, engagement, and deployability. To address challenges with ECF, an occupational therapist providing rehabilitation services to CAF SMs created and delivered Brain Bootcamp – an integrated behavioural health intervention for CAF SMs who sustained an mTBI or more serious traumatic brain injury (TBI) and had reduced ECF. Although anecdotal post-intervention feedback is favourable, Brain Bootcamp’s impact on ECF in individuals with mTBI or TBI, mental health diagnoses, or both has yet to be determined. This study aimed to determine whether Brain Bootcamp improves cognitive performance, reduces mTBI- and TBI-related symptoms, and increases external aid utilization among CAF SMs with reduced ECF. Methods: We conducted a quasi-experimental study of clinical outcomes collected from 55 participants who participated in Brain Bootcamp. Measures used to determine changes in client ECF before and after the intervention included the Montreal Cognitive Assessment, Rivermead Post-Concussion Symptom Questionnaire, and External Aids Utilization Survey. Results: Statistically significant changes pre- and post-intervention were observed, including improved cognitive performance, reduced self-reported mTBI or TBI symptoms, and increased external aid utilization. Discussion: Brain Bootcamp may have a positive effect on ECF. Such improvements can enable CAF SMs to be operationally ready for military service and have greater overall well-being. Brain Bootcamp appears to be a promising ECF-enhancing intervention.