Introduction <p>Physical activity is internationally recommended as an effective component of inflammatory arthritis (IA) care. It contributes to managing IA symptoms, enhancing quality of life, and reducing cardiovascular disease risk. However, many individuals with IA are insufficiently active to realize these multi-faceted benefits. Supporting physical activity behavior change remains a major challenge within IA care. Therefore, we conducted an umbrella review to understand current evidence on: (1) physical activity levels and associated patient characteristics, (2) barriers and facilitators, and (3) effectiveness and characteristics of physical activity behavior change interventions.</p> Methods <p>An umbrella review approach captured review-level evidence and provided big picture insights on the physical activity behavior change research landscape in IA. A systematic search for physical activity, IA, review articles, and physical activity outcomes was completed using EMBASE, MEDLINE, CINAHL, and SPORTDiscus. Article selection was completed by 3 authors using Covidence, followed by data extraction of article characteristics, research methods, populations and interventions, and key findings. After assessing study overlap between reviews and methodological quality (AMSTAR-2), a narrative synthesis was completed to summarize evidence on each of the 3 topics of interest.</p> Results <p>32 reviews covering 421 original articles, were included in the umbrella review. Of these, 7 were related to topic 1, 6 to topic 2, 15 to topic 3, and 4 to more than one topic. Individuals with IA frequently reported lower physical activity levels or decreased intensity compared to adults without IA. Physical function, education level, motivation, and physical activity history were associated with current physical activity in rheumatoid arthritis and spondyloarthritis. Behavioral barriers (symptoms, safety concerns) and facilitators (effective treatment, self-efficacy) were noted. Interventions using digital technology, health coaching, and other components can effectively increase physical activity behaviors, though comparative effectiveness data was lacking. AMSTAR-2 overall confidence ratings were low or critically low for 13/15 reviews of physical activity interventions.</p> Conclusions <p>The umbrella review provided a comprehensive overview of physical activity behavior change research in IA. Findings highlighted the need to improve physical activity support, leveraging effective intervention strategies in IA care. Given low overall confidence ratings, further high-quality research is needed to understand behaviors and intervention effects long-term, compare effectiveness of intervention strategies, support underserved populations with lower physical activity levels and greater barriers, and inform clinical recommendations.</p>