Ubrogepant is a novel, oral calcitonin gene-related peptide receptor antagonist currently under US Food and Drug Administration (FDA) review for the acute treatment of migraine attacks. This double-blind, four-period crossover study compared the cardiac repolarization effect of therapeutic (100 mg) and supratherapeutic (400 mg) ubrogepant doses vs. placebo in healthy adults. Moxifloxacin 400 mg was used as an open-label active control, and the primary end point was change from baseline in Fridericia-corrected QT intervals (ΔQTcF). Assay sensitivity was demonstrated via statistically significant QTcF prolongation with moxifloxacin vs. placebo. After single oral doses of ubrogepant, the least squares mean placebo-corrected ΔQTcF (ΔΔQTcF) and 90% confidence intervals (CIs) did not exceed the 10-millisecond regulatory threshold at any timepoint. The 90% CI upper bounds were 2.46 milliseconds and 2.69 milliseconds for ubrogepant 100 and 400 mg, respectively. Categorical and concentration-based analyses were consistent with the primary result, showing no significant impact of ubrogepant on cardiac repolarization.