A Bayesian network meta-analysis was conducted to examine the radiographic and clinical efficacy of the Janus kinase (JAK) inhibitors tofacitinib, baricitinib, upadacitinib, and filgotinib and the biologic disease-modifying antirheumatic drug (bDMARD) adalimumab (all given with methotrexate [MTX]) in patients with rheumatoid arthritis (RA) and an inadequate response to MTX (MTX-IR). The PubMed database was systematically searched to identify relevant randomized controlled trials. Efficacy outcomes included the modified total Sharp score (mTSS), erosion, joint space narrowing, 70% improvement in American College of Rheumatology criteria (ACR70), Boolean remission, Clinical Disease Activity Index (CDAI) score ≤ 2.8, and Simplified Disease Activity Index (SDAI) score ≤ 3.3. Five studies were identified using the inclusion criteria, and two additional publications presented further results from one of the five studies, with the total meta-analysis population comprising 6933 patients. Among all JAK inhibitors analyzed and the bDMARD adalimumab, filgotinib 200 mg had the highest probability of being the treatment with the greatest improvement in mTSS versus placebo at 48/52 weeks, followed by filgotinib 100 mg, adalimumab 40 mg, baricitinib 4 mg, and upadacitinib 15 mg. Filgotinib 200 mg also had the highest probability of being the treatment with the greatest improvement in erosion and joint space narrowing at 48/52 weeks versus the same comparators. At 12 weeks, filgotinib 200 mg had the highest probability versus other JAK inhibitors and adalimumab of achieving clinical remission (CDAI ≤ 2.8 and SDAI ≤ 3.3). Varying treatments had the highest probability of achieving other efficacy outcomes of interest at 12, 24/26, and 48/52 weeks. In the absence of head-to-head comparisons, this analysis provides valuable evidence for the role of filgotinib in the treatment of patients with MTX-IR RA.