Moderately active RA is associated with poor patient outcomes. Despite this, some health systems have restricted access to advanced therapies to those with severe RA. There is also limited evidence of the efficacy of advanced therapies in the moderately active RA population. This post-hoc analysis from four phase 3 trials explored the efficacy of upadacitinib (UPA) for moderately active RA. Patients included in this analysis received UPA 15 mg once daily [monotherapy after switching from MTX or in combination with stable background conventional synthetic DMARDs (csDMARDs)] or placebo. Clinical, functional and radiographic outcomes were analysed separately for patients with moderate disease activity {28-joint count DAS using CRP [DAS28(CRP)] of >3.2 and ≤5.1} and severe disease activity [DAS28(CRP) >5.1]. Patients with moderate disease activity who received UPA 15 mg (combination or monotherapy) after an inadequate response to biologic DMARDs and/or csDMARDs were significantly more likely to achieve a 20% improvement in the ACR response criteria, low disease activity status [DAS28(CRP) ≤ 3.2] or clinical remission [DAS28(CRP) < 2.6] by week 12/14 vs placebo. Statistically significant improvements in patient-reported functioning and pain from baseline were observed for UPA 15 mg vs placebo at week 12/14. Radiographic progression was also significantly reduced at week 26 compared with placebo. Similar improvements were observed for severe disease. This analysis provides support for the use of UPA for the treatment of patients with moderate RA. ClinicalTrials.gov: SELECT-NEXT: NCT02675426; SELECT-COMPARE: NCT02629159; SELECT-MONOTHERAPY: NCT02706951; SELECT-BEYOND: NCT02706847.