Anxiety is now recognized as one of the most common conditions that co‐occur with autism. While there has been increased research describing the typical and autism‐specific anxiety symptomatology and assessing the effectiveness of potential interventions, there has been less research exploring the impact that elevated anxiety may have on an individual and their quality of life (QoL). This study aimed to explore the impact of anxiety on the QoL in children on the autism spectrum. Children and young adolescents on the spectrum were invited to participate in a self‐report study measuring anxiety and health‐related QoL (HRQoL). The sample consisted of 71 children, aged 6–13. Children who scored above the cut off for elevated anxiety on the autism‐specific measure of anxiety (ASC‐ASD) had poorer total HRQoL and poorer scores on the social, emotional, physical, and school functioning QoL domains. Regression analyses indicate that children's self‐reported ratings of difficulties with uncertainty on the ASC‐ASD predicted all domains of HRQoL, with higher levels of difficulty with uncertainty predicting poorer HRQoL. Elevated levels of anxious arousal were also predictive of poorer physical functioning. This study highlights the importance of exploring the impact of anxiety on individuals on the spectrum and suggests that using carefully planned interventions to reduce difficulties with uncertainty may be a potential way to work toward improving the QoL of children on the spectrum.