Background: There has been extensive research into adverse childhood experiences (ACEs), however, less consideration has been given to the prevalence and impact of ACEs for staff working with people with intellectual disabilities. Method: Participants were staff employed by agencies that care for people with intellectual disabilities. An online survey collected demographic information and measures of ACEs, resilience, trauma-informed organisational climate, burnout and secondary traumatic stress. Correlation, regression, mediation and moderation analyses were used. Results: 81.7% of 109 participants had experienced at least one ACE. Burnout, secondary traumatic stress and resilience were greater in the present study than in comparable samples. Trauma-informed organisational climate significantly predicted burnout and secondary traumatic stress. Resilience significantly predicted burnout. Conclusions: Staff working with people with intellectual disabilities are likely to have experienced ACEs. Working in a trauma-informed organisational climate and resilience may be effective avenues for reducing burnout and secondary traumatic stress.