BACKGROUND: The COVID-19 pandemic has led to abrupt restrictions of life-space mobility. The impact of shelter-in-place orders on older adults' health and well-being is still unclear. OBJECTIVE: To investigate the relationship between life-space mobility and quality of life (QoL) in older adults with and without frailty during the COVID-19 pandemic. DESIGN: Multicenter prospective cohort study based on structured telephone interviews. SETTING: Four geriatric outpatient clinics in the metropolitan area of Sao Paulo, Brazil. PARTICIPANTS: 557 community-dwelling adults aged 60 years and older. MEASUREMENTS: The Life-Space Assessment was used to measure community mobility before and during the COVID-19 pandemic, and a previously validated decrease of ≥ 5 points defined restricted life-space mobility. Frailty was assessed through the FRAIL (fatigue, resistance, ambulation, illnesses, and loss of weight) scale. The impact of shelter-in-place orders on QoL was evaluated with the question «How is the COVID-19 pandemic affecting your QoL?», to which participants could respond «not at all», «to some extent», or «to a great extent». We used ordinal logistic regressions to investigate the relationship between restricted life-space mobility and impact on QoL, adjusting our analyses for demographics, frailty, comorbidities, cognition, functionality, loneliness, depression, and anxiety. We explored whether frailty modified the association between life-space mobility and impact on QoL. RESULTS: Participants were on average 80±8 years old, 65% were women, and 33% were frail. The COVID-19 quarantine led to a restriction of community mobility in 79% of participants and affected the QoL for 77% of participants. We found that restricted life-space mobility was associated with impact on QoL in older adults during the pandemic, although frailty modified the magnitude of the association (P-value for interaction=0.03). Frail participants who experienced restricted life-space mobility had twice the odds of reporting an impact on QoL when compared with non-frail individuals, with respective adjusted odds ratios of 4.20 (95% CI=2.36-7.50) and 2.18 (95% CI=1.33-3.58). CONCLUSION: Older adults experienced substantial decreases in life-space mobility during the COVID-19 pandemic, and this unexpected change impacted their QoL. Providers should be particularly watchful for the consequences of abrupt life-space restrictions on frail individuals.