Background: Early cardiovascular complications after non-traumatic intracerebral hemorrhage (ICH) contribute to short-term morbidity and mortality, yet reliable prognostic markers remain limited. We examined the association between admission serum albumin and 30-day cardiovascular complications after ICH, including dose–response patterns and consistency across subgroups. Methods: In this retrospective cohort study using the TriNetX US Collaborative Network, adults hospitalized with ICH (ICD-10-CM I61) and serum albumin measured within 24 h of admission were stratified into reduced (≤3.4 g/dL) and normal (≥3.5 g/dL) groups and balanced by 1:1 propensity score matching on demographics, cardiovascular comorbidities, ICH severity, neurosurgical procedures, and medications. The primary outcome was a 30-day composite of all-cause death, acute myocardial infarction, heart failure, atrial fibrillation or flutter, ventricular arrhythmias, and Takotsubo cardiomyopathy. Sensitivity analyses addressed age, sex, comorbidity burden, and chronic hypoalbuminemia. Results: Of 241,228 patients, 94,925 (39%) had reduced albumin; 79,751 were retained per group after matching. The composite outcome occurred in 40.4% versus 33.3% (HR 1.28, 95% CI 1.26–1.30; p < 0.0001). Reduced albumin was associated with higher all-cause mortality (HR 1.50), myocardial infarction (HR 1.36), heart failure (HR 1.22), ventricular arrhythmias (HR 1.41), and Takotsubo cardiomyopathy (HR 1.41; all p < 0.005). Atrial fibrillation or flutter did not differ (HR 1.02; p = 0.779). A dose–response was observed, with severe hypoalbuminemia conferring greater composite risk (HR 1.49) than mild (HR 1.16). Findings were consistent across all sensitivity analyses. Conclusions: Reduced admission serum albumin is independently associated with higher short-term mortality and cardiovascular complications after ICH and may aid early risk stratification. Prospective studies are needed to clarify its utility.