BACKGROUND: Filgotinib is a small molecule with preferential inhibition of Janus kinase type 1, approved for the treatment of ulcerative colitis in Scotland in May 2022. We present the first real-world experience on its use in clinical practice. METHODS: In this retrospective, observational, cohort study we assessed patients with active ulcerative colitis who received filgotinib in NHS Lothian, Scotland. Baseline demographic, phenotype, and follow-up data were collected via review of electronic medical records. RESULTS: We included 91 patients with median treatment duration of 39 weeks (interquartile range [IQR] 23-49). Among the cohort, 67% [61/91] were biologic- and small molecule-naive, and 20.9% [19/91] had failed one and 12.1% [11/91] two or more classes of advanced therapy. Of the biologic- and small molecule-naive patients, 18% [11/61] were also thiopurine-naive. Clinical remission [partial Mayo score <2] was achieved in 71.9% [41/57] and 76.4% [42/55] of patients at Weeks 12 and 24 respectively. Biochemical remission [C reactive protein </=5 mg/L] was achieved in 87.3% [62/71] at Week 12 and 88.9% [40/45] at Week 24. Faecal biomarker [calprotectin <250 microg/g] remission was achieved in 82.8% [48/58] at Week 12 and 79.5% [35/44] at Week 24. At the end of follow-up, median 42 weeks [IQR 27-50], 82.4% [75/91] of patients remained on filgotinib. Severe adverse events leading to drug discontinuation occurred in 2.2% [2/91] and there were 8.8% [8/91] moderate adverse events that required temporary discontinuation. CONCLUSION: These are the first reported data on the real-world efficacy and safety of filgotinib in ulcerative colitis. Our findings demonstrate that filgotinib is an effective and low-risk treatment option for these patients.