Background: Little is known about the work-related well-being of applied behaviour analysis (ABA) therapists who work in school-based contexts and deliver ABA interventions to children with autism. Methods: A questionnaire on work-related stress (burnout), general distress, perceived supervisor support and coping was completed by 45 ABA therapists across six schools in the UK. Results: Around 42% of ABA therapists reported low levels of personal accomplishment at work, 13% reported high levels of emotional exhaustion and 40% met criteria for experiencing high levels of general distress. Wishful thinking coping was predictive of higher emotional exhaustion burnout and depersonalisation, and lower personal accomplishment. Conclusions: Given that a wishful thinking approach to coping may contribute to experiencing stress at work, it is important to consider support interventions for ABA therapists that may enhance their well-being. Mindfulness and acceptance-based strategies in particular may be relevant to the support of ABA therapist well-being.