Objectives: Defined as attending work while ill, presenteeism is highly prevalent and has negative consequences such as reduced productivity and lower well-being for workers. This study aims to estimate the prevalence of presenteeism among Korean workers during the COVID-19 pandemic and identify the risk factors. Material and Methods: Using data extracted from the second wave of the Korea Health Panel Survey in 2019–2021, this study assessed experience of presenteeism and the number of presenteeism days as the dependent variable. Independent variables included gender, age group, educational level, employment status, household income quartile, and the presence of chronic conditions. Two generalized estimating equation models were used. Results: In 2019, 30.6% of participants reported experiencing presenteeism; this decreased to 17.9% in 2020 and 13.5% in 2021. The mean number of presenteeism days decreased from 2.30 days in 2019 to 1.46 days in 2020 and to 1.04 days in 2021. The participants were less likely to experience presenteeism in 2020 and 2021 than in 2019 (OR = 0.48 and OR = 0.36, respectively, p < 0.001). The risk of presenteeism is higher among women, younger age groups, participants with regular employment or on-contract positions, lower income, and chronic conditions than their counterparts. The number of presenteeism days significantly decreased in 2020 and 2021 (β = –0.44 and –0.78, respectively, p < 0.001). Conclusions: Workers were less likely to experience presenteeism in 2020 and 2021 than in 2019, and the number of presenteeism days decreased during the COVID-19 pandemic. The risk of presenteeism was associated with worker characteristics. Int J Occup Med Environ Health. 2024;37(6):617–29