Background: Evidence on the association between obesity parameters, including body mass index (BMI) and waist circumference (WC), and osteoarthritis is limited. This study aimed to investigate these associations in Korean adults. Methods: This nationwide cross-sectional study used data from 24,101 adults aged ≥19 years who participated in the Korea National Health and Nutrition Examination Survey 2016–2020. Odds ratios (ORs) and 95% confidence intervals (CIs) for osteoarthritis according to BMI and WC were analyzed using multivariable logistic regression analyses. Results: The prevalence of osteoarthritis was higher in individuals with general (10.0%) and abdominal obesity (12.8%) compared with those without. Greater BMI and WC were associated with a higher prevalence (P<0.001) and risk of osteoarthritis (Model 3, P for trend <0.001). Individuals with general and abdominal obesity were associated with a 1.50-fold (OR, 1.50; 95% CI, 1.35–1.67) and 1.64-fold (OR, 1.64; 95% CI, 1.47–1.84) increased risk of osteoarthritis, compared with those without. Similar associations were observed in subgroups according to age, sex, smoking status, and presence of diabetes mellitus. The odds of osteoarthritis 1.73-fold increased (OR, 1.73; 95% CI, 1.53–1.95) in individuals with both general and abdominal obesity compared with those without any of them. Conclusion Greater BMI, WC, and general and abdominal obesity were associated with an increased risk of osteoarthritis in Korean adults. Appropriate management of abdominal and general obesity may be important to reduce the risk of osteoarthritis.