Ulcerative colitis (UC) is an intestinal inflammatory disorder. Long non-coding RNAs (lncRNAs) are collectively involved in UC. This study is designed to explore the roles of lncRNA (small nucleolar RNA host gene 5) SNHG5 in UC. Gene or microRNA (miRNA) expression was detected using RT-qPCR and western blot, respectively. Cellular functions were analyzed by cell counting kit 8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry, and the terminal deoxyribonucleotidyl transferase (TDT)-mediated dUTP-digoxigenin nick end labeling (TUNEL) assays. Lactate dehydrogenase (LDH) content was determined by a cell cytotoxicity assay. The interactions between miR-375 and SNHG5 or Janus kinase-2 () were verified by a luciferase reporter assay. SNHG5 was up-regulated in intestinal mucosa tissues of UC patients as well as tumor necrosis factor alpha-treated (TNF-α-treated) young adult mouse colon (YAMC) cells. Down-regulated SNHG5 promoted cell proliferation and inhibited apoptosis of YAMC cells. miR-375 was verified to be a target of SNHG5 and was suppressed by TNF-α treatment in YAMC cells. Over-expression of miR-375 restored YAMC cellular functions. Additionally, miR-375 targeted , which was up-regulated by TNF-α treated YAMC cells. Up-regulation of induced the dysfunction of YAMC cells. Knockdown of SNHG5 promoted the proliferation and suppressed the apoptosis of YAMC cells via regulating miR-375/ axis. Therefore, knockdown of SNHG5 may be a promising therapy for UC.