<b><i>Introduction:</i></b> There have been limited reports on the clinical efficacy of golimumab (GLM) in Japanese patients with ulcerative colitis (UC) in real clinical practice. This study aimed to explore the real-life effectiveness and factors associated with response to GLM in Japanese patients with UC. <b><i>Methods:</i></b> This observational, retrospective, multicenter study was conducted in hospitals with expertise in inflammatory bowel disease treatment. Sixty-three patients treated with GLM and active UC were included in the analysis. Clinical remission (CR) (partial Mayo (pMayo) score ≤2) in the induction and maintenance phases after GLM treatment and associated factors were evaluated. <b><i>Results:</i></b> The proportion of patients achieving CR in the induction and maintenance phases was 41.3% (26/63) and 46.0% (29/63, the last observation carried forward method was used for patients who discontinued treatment for reasons other than inadequate response), respectively. The median pMayo score was 5 (interquartile range (IQR): 4–6) at baseline, 3 (IQR: 1–5) in the induction phase, and 1 (IQR: 0–3) in the maintenance phase. Hemoglobin, platelet, and C-reactive protein levels changed, consistent with the pMayo score. Multivariate logistic analysis revealed that biologic-naive status was an independent factor associated with CR in the induction (<i>p</i> = 0.0200) and maintenance (<i>p</i> = 0.0459) phases, and a disease duration of >60 months until GLM initiation was associated with CR in the induction phase (<i>p</i> = 0.0427). <b><i>Conclusions:</i></b> The effectiveness of GLM in daily clinical practice has been confirmed in Japanese patients with active UC. Biologic-naive patients responded more to GLM in the induction and maintenance phases, and patients with disease duration of >60 months until initiation of GLM were more responsive in the induction phase.