During the COVID-19 pandemic, it quickly became clear that people living with overweight and obesity (OAO) have a higher risk for more severe health outcomes. The objective of this study is to investigate how the health and economic impacts of COVID-19 are exacerbated by OAO. We estimated economic impacts of COVID-19 associated with OAO for eight countries using a cost-of-illness approach from a limited societal perspective. Direct medical costs and premature mortality costs between 2020 and 2030 were estimated. Country-specific data were sourced from published studies and global databases. Additional COVID-19 hospitalizations, ICU admissions, and deaths among the population with OAO accounted for approximately 20% of hospitalizations, 43% of ICU admissions, and 17% of deaths from COVID-19 in 2020 and 2021 on average across the eight countries. As a percent of GDP, additional treatment and premature mortality costs ranged from between 0.0003% in Thailand to 0.62% in Brazil in 2020 and between 0.009% in Australia to 0.56% in Brazil in 2021. In future COVID-19 prevalence scenarios, keeping OAO prevalence at 2019 levels or reducing it by 50% will translate into average annual reductions of 17.4%-18.5% and 40.8%-41.4% in additional costs respectively between 2022 and 2030 across the eight countries. This study provides initial evidence on the significant economic impacts of COVID-19 on populations with OAO. Our findings support the need for strengthened political commitment and adequate prioritization of OAO prevention and reduction interventions to help increase resilience to public health emergencies in these and other countries.