Context: Traditional lifestyle factors, such as smoking and poor diet, have been associated with adverse outcomes in people with rheumatoid arthritis (RA). However, the individual and combined effect of emerging lifestyle factors, such as sleep duration and sedentary behaviour, remains unclear. Objective: To examine the association between an extended lifestyle score (based on traditional and emerging lifestyle factors) and all-cause mortality and major adverse cardiovascular events (MACE) in an RA population. Study Design: Longitudinal data analysis. Dataset: UK Biobank is a population-based cohort with 502,503 participants (aged between 37-73). Population Studied: 5,295 participants (1.1%) self-reported RA and lifestyle score data. Participants with RA were assigned one point each for unhealthy lifestyle behaviours relating to: alcohol intake, diet, physical activity, sleep duration, smoking and television viewing time, giving a lifestyle score of 0-9. Participants were then categorised as having most healthy (score 0-2), moderately healthy (score 3-5) and least healthy (score 6-9) lifestyles. Methods: Cox proportional hazards models were used and all analyses were adjusted for age, sex, socioeconomic status, body mass index and other long-term condition count. Intervention/Instrument: None. Outcome Measures: All-cause mortality and MACE. Results: Participants had a mean age of 59 (standard deviation: 7.10) and were 70% female. There were 390 (7.37%) deaths and 295 (5.57%) MACE recorded. The adjusted hazard ratio (HR) in the moderately healthy category, compared with the most healthy (reference) category, was 1.23 (95% confidence interval (CI) 0.99-1.51) for all-cause mortality and 1.39 (95% CI 1.09-1.77) for MACE. The adjusted HR for all-cause mortality in the least healthy category, compared with the most healthy (reference) category, was 2.42 (95% CI 1.42-4.12) and 2.04 (95% CI 1.03-4.06) for MACE. Conclusions: Unhealthy lifestyle factors are associated with higher risk of adverse health-related outcomes in people with RA. People in the least healthy category experienced over twice the risk of all-cause mortality or MACE compared to those in the most healthy category. Examining the impact of combined traditional and emerging lifestyle factors may inform health policy on more comprehensive lifestyle advice for people with RA which in turn may help reduce their risk of adverse health-related outcomes.