The relationship between social determinants of health (SDH) and disease outcomes in rheumatoid arthritis (RA) is not well documented. Data were extracted from the Ontario Best Practices Research Initiative (OBRI) registry for patients between January 2008 and April 2022. Adjusted mixed models analysis was used to investigate the effect of baseline SDH on disease activity (Clinical Disease Activity Index (CDAI)) and functional disability (Health Assessment Questionnaire-Disability Index (HAQ-DI)) 12months after enrollment. The analyses were completed on multiple imputed data. There were 2651 patients with a mean age of 58.1years (SD 12.9). The majority (77.8%) were female. Greater improvements in physical function were seen in patients who were full-time employed (difference = - 0.20; 95% CI - 0.28, - 0.11), part-time employed (difference = - 0.10; 95% CI - 0.19, - 0.02), or retired (difference = - 0.17; 95% CI - 0.25, - 0.08), compared to unemployed, those with highest income ($75,000 or more) (difference = - 0.23; 95% CI - 0.37, - 0.09). Caucasian was also associated with a positive impact on functional ability (difference = - 0.09; 95% CI - 0.17, - 0.02). In contrast, smokers had smaller improvements in physical function (difference = 0.07; 95% CI 0.002, 0.14). Interestingly, women had greater improvement in CDAI (difference = - 2.40; 95% CI - 3.29, - 1.51), while they reported less improving in their physical function (difference = 0.33; 95% CI 0.27-0.39). Achieving CDAI low disease activity/remission state was also more common in females. Our findings suggest that disease activity and functional disability are affected by different SDH factors. The effects of SDH should be better understood and addressed by rheumatologists to provide equitable healthcare for all patients with RA. Key points • This study explored a comprehensive panel of social determinants of health and their relationship to clinical outcomes. • Previously unreported factors such as employment status and income were found to influence clinical outcomes. • Our findings can help physicians to identify high-risk patients who may benefit from additional attention to their social background.