Background/Objectives: Albumin supplementation is widely used for hypoalbuminemia treatment in patients with critical illness, especially those with cirrhosis. However, studies have demonstrated that routine albumin administration is not always advantageous. We examined how albumin supplementation affects survival outcomes in patients with sepsis with hypoalbuminemia. Methods: This study was conducted by researchers in Taiwan using data from the TriNetX research platform, covering the period from 1 April 2014 to 30 April 2024. This platform aggregates real-world data from healthcare organizations worldwide. From this dataset, 1,147,433 patients who developed sepsis and hypoalbuminemia with albumin levels <3.5 g/dL were identified. The study population was stratified into two groups on the basis of whether they received albumin infusion or not. To compare outcomes, hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated between propensity-score-matched patients who did and did not receive albumin supplementation. Subgroup analysis by albumin levels was conducted. Results: Albumin infusion was linked to increased risks of 30-day mortality (HR [95% CI] = 1.800 [1.774–1.827], p < 0.05), shock (HR [95% CI] = 1.436 [1.409–1.465], p < 0.05), septic shock (HR [95% CI] = 1.384 [1.355–1.415], p < 0.05), hypovolemic shock (HR [95% CI] = 1.496 [1.391–1.608], p < 0.05), cardiogenic shock (HR [95% CI] = 1.553 [1.473–1.637], p < 0.05), heart failure (HR [95% CI] = 1.098 [1.080–1.116], p < 0.05), and pulmonary edema (HR [95% CI] = 1.479 [1.438–1.520], p < 0.05). The subgroup analysis by albumin levels revealed a trend of increased mortality risk with albumin supplementation in patients with high baseline albumin levels. Conclusions: Patients with sepsis with hypoalbuminemia who received albumin supplementation exhibited high 30-day mortality rates and increased risks of shock, heart failure, and pulmonary edema compared with those who did not. These findings indicate that routine albumin administration may be linked with unfavorable outcomes in these patients.