Background: Chronic breathlessness is a prevalent disabling syndrome affecting many people for years. Identifying the impact of chronic breathlessness on people's activities in the general population is pivotal for designing symptom management strategies. Objective: This study aimed to evaluate the association between chronic breathlessness and activities respondents identify can no longer be undertaken (''activities forgone''). Design: This population-based cross-sectional online survey used a market research company's database of 30,000 registrants for each sex, generating the planned sample size-3000 adults reflecting Australia's 2016 Census by sex, age group, state of residence, and rurality. Setting/Subjects: The population of focus (n = 583) reported a modified Medical Research Council (mMRC) breathlessness scale ‡1 and experienced this breathlessness for ‡3 months. Measurements: Activities forgone were categorized by mMRC using coding derived from the Dyspnea Management Questionnaire domains. Activities were classified as ' 'higher/lower intensity' ' using Human Energy Expenditure scale. Results: Respondents were male 50.3%; median age 50.0 (IQR 29.0); with 66% living in metropolitan areas; reporting 1749 activities forgone. For people with mMRC 1 (n = 533), 35% had not given up any activity, decreasing to 9% for mMRC 2 (n = 38) and 3% for mMRC 3-4 (n = 12). Intense sport (e.g., jogging and bike riding) was the top activity forgone: 42% (mMRC 1), 32% (mMRC 2), and 36% (mMRC 3-4). For respondents with mMRC 3-4, the next most prevalent activities forgone were ''sexual activities'' (14%), ''lower intensity sports'' (11%), and ''other activities'' (11%). Conclusions: People progressively reduce a wide range of activities because of their chronic breathlessness.