Background: Osteoarthritis (OA) is a leading cause of disability worldwide. China is undergoing rapid population ageing, yet how its OA burden compares with that of other G20 countries over time has not been fully quantified. Methods: Using data from the Global Burden of Disease 1990–2023 study, we described OA incidence, prevalence, and disability-adjusted life years (DALYs) for China and the aggregated G20. We analyzed age-standardized rates (ASRs) and absolute numbers for adults ≥ 30 years by year, age group, and anatomical site (knee, hip, hand, other). Temporal trends were summarized by estimated annual percentage change. We visualized overall time trends in incidence, age-specific rates, and case numbers in 2023, and the distribution of OA subtypes in China versus the G20. Results: From 1990 to 2023, China’s age-standardized incidence rate (ASIR) increased from 487.1 to 550.2 per 100,000, while annual incident cases rose from 4.68 to 11.90 million. Age-standardized prevalence and DALY rates also rose modestly, but absolute numbers of prevalent cases and DALYs more than doubled. Compared with the G20 aggregate, China showed steeper increases in both incidence and case numbers. In 2023, incidence, prevalence, and DALY rates climbed steadily with age in both China and the G20, with incidence peaking at 55–64 years, prevalence at 85–94 years, and DALY rates at 70–79 years; the bulk of cases occurred between 50 and 74 years. Across anatomical sites, knee OA contributed the largest share of burden, followed by hand, other sites, and hip OA, with a broadly similar ranking in China and the G20. Conclusion: From 1990 to 2023, China experienced a marked rise in OA burden, driven mainly by population growth and ageing. Older adults, especially those with knee and hand OA, carry the greatest share of the disease. Healthcare planning should prioritize age-friendly prevention, early diagnosis, and long-term rehabilitation.