Purpose: The purpose of the study was to evaluate vision-related quality of life and visual ability in patients with OPA1 autosomal dominant optic atrophy (ADOA). Methods: This cross-sectional, observational study included 145 participants with a mutation in the OPA1 gene associated with ADOA, 63 mutation-free first-degree relatives and 92 healthy subjects unrelated to the families. Participants underwent a clinical eye examination, and adult participants completed the National Eye Institute Visual Function Questionnaire (NEI-VFQ-39), while children completed the Cardiff Visual Ability Questionnaire for Children (CVAQC). Results: In adults with ADOA, both mean visual acuity (VA) and mean contrast sensitivity (CS) were significantly inferior to both first-degree relatives and unrelated controls (p < 0.001). In children with ADOA, mean VA was significantly lower compared with first-degree relatives (p = 0.0052), whereas CS was not (0.127). Adults with ADOA scored lower than both comparator groups on composite score (p < 0.001), general health subscale (p = 0.0075) and all vision-related subscales (p < 0.001) except the ocular pain subscale (p = 0.2). In children with ADOA, the median CVAQC logit score was significantly lower compared with first-degree relatives (p = 0.037). The science lessons subscale was significantly lower for children with ADOA compared with first-degree relatives (p = 0.046), as well as the language lessons subscale (p = 0.038). For adults, composite score and subscale scores were significantly associated with both VA, CS and fixation status. Conclusion: OPA1 mutation is associated with lower quality of life and visual ability in patients with ADOA compared with both first-degree relatives and unrelated controls. VA, CS and fixation status affect quality of life in patients with ADOA.