Patients requiring extracorporeal life support (ECLS) post-Norwood operation constitute an extremely high-risk group. We retrospectively described short-term outcomes, functional status, and assessed risk factors for requiring ECLS post-Norwood operation between January 2010 and December 2020 in a high-volume center. During the study period, 269 patients underwent a Norwood procedure of which 65 (24%) required ECLS. Of the 65 patients, 27 (41.5%) survived to hospital discharge. Mean functional status scale (FSS) score at discharge increased from 6.0 on admission to 8.48 (p < 0.0001). This change was primary in feeding (p < 0.0001) and respiratory domains (p = 0.017). Seven survivors (26%) developed new morbidity, and two (7%) developed unfavorable functional outcomes. In the regression analysis, we showed that patients with moderate—severe univentricular dysfunction on pre-Norwood transthoracic echocardiogram (odds ratio [OR] = 6.97), modified Blalock Taussig Thomas (m-BTT) shunt as source of pulmonary blood flow (OR = 2.65), moderate—severe atrioventricular valve regurgitation on transesophageal echocardiogram (OR = 8.50), longer cardiopulmonary bypass time (OR = 1.16), longer circulatory arrest time (OR = 1.20), and delayed sternal closure (OR = 3.86), had higher odds of requiring ECLS (p < 0.05). Careful identification of these risk factors is imperative to improve the care of this high-risk cohort and improve overall outcomes.