Autistic children and adolescents experience a range of co-morbidities, including diagnoses of mental illness. Animal-assisted therapies have advanced rapidly over recent years as an effective and accessible intervention for autistic children and adolescents with various health issues. Horses offer a unique opportunity for interaction as the young person can physically ride the animal, thus creating a therapy with different physical interactions from other animals. This qualitative study had two main aims: first, to understand parents’ experiences of their autistic child’s involvement with horse-based therapies; and second, to understand the experiences of the staff of organisations offering horse-based therapies to those on the autism spectrum. Twelve interviews were conducted with six parents across four interviews (four mothers and two fathers), and eight staff of equine therapy services in eight individual interviews, to understand their perceptions of the child’s experience with horse riding and the perceived mental health impacts. Three emergent themes were prominent among parents and service providers alike: physical and social benefits, including health, self-management skills and social skills; protecting mental health; and recommendations for improvements and accessibility of horse-based therapies. Specifically, service providers with long-standing associations with horse-based therapies saw the actual and potential benefits of horse-based therapies for autistic children, particularly in promoting happiness, calm, resilience, and good mental health.