Children on the autism spectrum often experience anxiety. Mindfulness is growing in popularity as a method to support children with anxiety; however, there is limited evidence on mindfulness for children on the autism spectrum. This study investigated the feasibility of a 10-week group-based mindfulness intervention for 14 children on the autism spectrum. A one-group pre-post design determined outcomes of anxiety (caregiver and child report), mindful attention, and wellbeing (child report). Interviews explored children’s and caregivers’ perceptions. There were no significant differences in outcomes post-intervention. Five themes were identified from interviews: (1) Children felt calmer; (2) Parents observed differences in anxiety; (3) Breathing and yoga helped; (4) Parents wanted more; and (5) Challenges and benefits of group intervention.