Background: Although heartburn and reflux are frequently reported in ulcerative colitis [UC], the correlation between UC and gastroesophageal reflux disease [GERD], and its complications, esophageal stricture and Barrett’s esophagus [BE], is not well understood. This study aims to examine the prevalence and associated risk of GERD and its complications within the UC population. Methods: We analyzed the National Inpatient Sample (NIS) dataset, consisting of 7,159,694 patients, comparing GERD patients with and without UC to those without GERD. We assessed the degree of colonic involvement in UC and the occurrence of esophageal complications. Bivariate analyses were conducted using the chi-squared test or Fisher exact test (two-tailed). Results: A higher prevalence of GERD (23.0% vs. 16.5%) and GERD phenotypes, such as non-erosive reflux disease (NERD) (22.3% vs. 16%) and erosive esophagitis (EE) (1.2% vs. 0.6%), was found in UC patients (p < 0.01), including pancolitis, proctitis, proctosigmoiditis, left-sided colitis, and indetermined UC (with undefined colonic involvement). UC patients were more likely to develop GERD (1.421), NERD (1.407), and EE (1.681) (p < 0.01). A higher prevalence of esophageal stricture (16.9 vs. 11.4 per 10,000 patients) and BE without dysplasia (94.5 vs. 39.3 per 10,000 patients) was found in UC (p < 0.05). The odds of developing BE without dysplasia were higher (1.892) in patients with UC (p < 0.01), including ulcerative pancolitis, proctitis, and indeterminate UC (OR of 1.657, 3.328, and 1.996, respectively) (p < 0.05). Conclusions: Our study demonstrates an increased risk of developing GERD and its complications in UC. This highlights the importance of vigilant monitoring and early intervention to minimize associated GERD-related risks in patients with UC.