Background Poor mental health in medical students is a global concern. Effective interventions are required, which are tailored towards the training-related stressors medical students experience. The Reboot coaching programme is an online, tailored intervention based on cognitive-behavioural principles. Aims To evaluate whether the Reboot coaching programme tailored for medical students was feasible and associated with improvements in mental health outcome indicators. Methods Medical students participated in two group online workshops and a one-to-one coaching call with a Reboot-trained licensed psychological therapist. Participants provided data at: baseline (T1), post-workshops (T2), post-coaching call (T3) and 4-month follow-up (T4). Outcome measures included resilience, confidence, burnout and depression. Feedback was provided regarding the workshops at T2. Results 115 participants (93/80.9% women; mage = 23.9; SD = 2.8) were recruited, 83 (72.2%) completed all intervention elements and 82 (71.3%) provided T4 data, surpassing recruitment and retention targets. There were significant improvements following baseline in resilience ( ps < .001), confidence ( ps < .001), burnout ( ps < .001) and depression ( ps ≤ .001). Most participants agreed the workshops imparted useful skills (n = 92; 99%) and would recommend Reboot to others (n = 89; 95.6%). Conclusions Existing interventions have produced mixed results regarding their effectiveness in improving medical students’ mental health. Reboot is a feasible intervention in this group which is associated with improvements in resilience, confidence, burnout and depression. Further controlled studies of Reboot are now needed.