This study provides a comprehensive analysis of the global burden and socioeconomic impact of knee osteoarthritis (KOA) from 1990 to 2019. The findings reveal that in 2019, there were approximately 364.58 million prevalent cases of KOA, with 225.16 million among females, 29.51 million incident cases, with 17.53 million among females, and 11.53 million disability-adjusted life years (DALYs), with 7.09 million among females. The Western Pacific Region had the highest endemicity, with 7,319.87 cases per 100,000 people, while Japan had the highest prevalence rate at 12,610.12 cases per 100,000 population. In 200 countries, the prevalence, incidence, and DALY rates of KOA were higher among females than males, and these rates increased with age up to the oldest age group. The prevalence was highest in high-middle sociodemographic index (SDI) countries, while the incidence and DALYs were highest in middle SDI countries. The study highlights significant variations in the burden of KOA across countries, with some countries having 10 times the burden of others. The prevalence, incidence, and DALYs of KOA were higher among females than males in most regions, except the United Arab Emirates. The study also shows that the burden of KOA increases with age, with the highest prevalence among individuals aged 80–84 years. The study emphasizes the need for increased awareness of KOA prevalence, incidence, and DALYs, particularly in the Western Pacific Region, and for health policy development to improve the efficiency, equity, and effectiveness of healthcare systems. The findings underscore the importance of addressing the socioeconomic impact of KOA and the need for targeted interventions to reduce its burden.This study provides a comprehensive analysis of the global burden and socioeconomic impact of knee osteoarthritis (KOA) from 1990 to 2019. The findings reveal that in 2019, there were approximately 364.58 million prevalent cases of KOA, with 225.16 million among females, 29.51 million incident cases, with 17.53 million among females, and 11.53 million disability-adjusted life years (DALYs), with 7.09 million among females. The Western Pacific Region had the highest endemicity, with 7,319.87 cases per 100,000 people, while Japan had the highest prevalence rate at 12,610.12 cases per 100,000 population. In 200 countries, the prevalence, incidence, and DALY rates of KOA were higher among females than males, and these rates increased with age up to the oldest age group. The prevalence was highest in high-middle sociodemographic index (SDI) countries, while the incidence and DALYs were highest in middle SDI countries. The study highlights significant variations in the burden of KOA across countries, with some countries having 10 times the burden of others. The prevalence, incidence, and DALYs of KOA were higher among females than males in most regions, except the United Arab Emirates. The study also shows that the burden of KOA increases with age, with the highest prevalence among individuals aged 80–84 years. The study emphasizes the need for increased awareness of KOA prevalence, incidence, and DALYs, particularly in the Western Pacific Region, and for health policy development to improve the efficiency, equity, and effectiveness of healthcare systems. The findings underscore the importance of addressing the socioeconomic impact of KOA and the need for targeted interventions to reduce its burden.