Rheumatoid arthritis (RA) is a long-term disorder that significantly impairs somatic, emotional, and psychological functioning. The objective of this review is to identify, appraise, and synthesize the effects of psychological interventions (e.g., cognitive behavioral therapy (CBT), emotional disclosure (ED), group therapy (GT), mindfulness (M), patient education (PE), and relaxation (R)) on biopsychosocial outcomes in the treatment of rheumatoid arthritis (RA). A systematic search of all relevant existing randomized clinical trials (RCTs) was conducted using the following online bibliographic databases: JSTOR, PubMed, PsycNET, and The Cochrane Library. Reference lists were searched for additional reports. The Cochrane Risk of Bias tool (RoB 2.0) was used to assess the risk of bias in the included studies. After the selection process, 57 articles were included and 392 were excluded. Three separate meta-analyses were conducted involving psychological interventions as the main variables, showing: (1) significant positive medium effect sizes for average values (Hedges-g = 0.399, Z = 0.399, = 0.009); (2) significant positive large effect sizes for maximum values (Hedges-g = 0.856, Z = 4.223, < 0.001); and (3) non-significant results for minimum values (Hedges-g = -0.047, Z = -0.335, = 0.738). These results demonstrate that, when grouped, psychological interventions are, on average, moderately effective in treating RA. Overall, this review shows consistent, supportive evidence that psychological interventions can significantly contribute to the standard medical care of RA patients. However, more high-quality, large-sample RCTs still need to confirm these findings.