Purpose: Ankle sprains and fractures are among the most common injuries sustained in active individuals, and they are associated with increased risk of developing ankle osteoarthritis (OA). Studies have demonstrated that ankle OA has a considerable impact on quality of life and disability. Individuals with ankle OA have similar health-related quality of life and disability as individuals with end-stage renal disease, radiculopathy and congestive heart failure. However, compared to these conditions, ankle OA affects younger individuals due to its post-traumatic nature. To date, research on impairments in ankle OA is limited to individuals with end-stage disease awaiting surgery. Little is known about the features of ankle OA in the general population, or the relationship between radiographic evidence of OA and symptoms or impairments. The primary aim of this study was to compare physical and self-report measures between individuals with symptomatic radiographic ankle osteoarthritis and asymptomatic individuals. Secondary aims were to compare these outcomes in asymptomatic individuals with and without radiographic evidence of ankle osteoarthritis, and to identify associations between outcomes and health-related quality of life. Methods: Thirty-one individuals with persistent ankle pain, stiffness and radiographic ankle osteoarthritis (symptomatic group) and 65 asymptomatic individuals (41 with radiographic ankle osteoarthritis and 24 with no radiographic ankle osteoarthritis) participated in this study (n=96). Participants completed the following physical outcome measures: timed walking, timed stair ascent and descent, ankle muscle strength, heel raise endurance, dorsiflexion range of motion, ankle arthrokinematics, foot posture index, and foot mobility. Self-reports measures included quality of life, function, disability, instability, kinesiophobia and physical activity. Results: Individuals with symptomatic ankle OA have slower walking speed, slower stairs ascent and decent, lower ankle muscle strength, lower heel raise endurance, and less dorsiflexion range of motion than asymptomatic individuals (all moderate to very large effects). Quality of life and self-report function were lower, and disability, instability and kinesiophobia were greater in individuals with symptomatic ankle OA than asymptomatic individuals (all moderate to large effects). There were no differences, or negligible effects, between individuals with symptomatic ankle OA and asymptomatic individuals for ankle arthrokinematics, foot posture index, foot mobility and self-report physical activity. With the exception of a small effect for less anterior displacement on arthrometry in asymptomatic individuals with radiographic ankle osteoarthritis, there were no differences in physical outcomes between asymptomatic individuals with and without radiographic ankle osteoarthritis. Quality of life, function, disability, kinesiophobia, ankle instability and physical activity were similar between asymptomatic groups. There were significant associations between ankle joint symptoms (ankle pain and/or stiffness) and stair ascent/descent times, and health-related quality of life. Conclusions: Symptomatic ankle osteoarthritis has a significant negative impact on quality of life, ankle function, ambulatory function and disability. The presence of radiographic joint degeneration without symptoms is not related to quality of life or physical impairments. Thus, ankle pain and stiffness, but not radiographic ankle joint OA, are associated with physical impairments and poor patient-reported outcomes in this population. The relationship between stair ascent and decent ability, ankle symptoms and impaired quality of life suggests the need to include stair ambulation in the assessment and management of patients with ankle OA.