evidence: The number of children affected by COVID-19-associated orphanhood and caregiver death is estimated to have increased by 90·0% (95% CrI 89·7–90·4) from April 30 to Oct 31, 2021, from 2 737 300 (95% CrI 1 976 100–2 987 000) to 5 200 300 (3 619 400–5 731 400). Between March 1, 2020, and Oct 31, 2021, 491 300 (95% CrI 485 100–497 900) children aged 0–4 years, 736 800 (726 900–746 500) children aged 5–9 years, and 2 146 700 (2 120 900–2 174 200) children aged 10–17 years are estimated to have experienced COVID-19-associated orphanhood. Globally, 76·5% (95% CrI 76·3–76·7) of children were paternal orphans, whereas 23·5% (23·3–23·7) were maternal orphans. In each age group and region, the prevalence of paternal orphanhood exceeded that of maternal orphanhood. Our findings show that numbers of children affected by COVID-19-associated orphanhood and caregiver death almost doubled in 6 months compared with the amount after the first 14 months of the pandemic. Over the entire 20-month period, 5·0 million COVID-19 deaths meant that 5·2 million children lost a parent or caregiver. Our data on children's ages and circumstances should support pandemic response planning for children globally.