The COVID-19 pandemic disproportionately affected ethnic minority populations and exacerbated preexisting health disparities. The current study aims to promote vaccine uptake among Mexican-origin youth from immigrant families by examining their time to COVID-19 vaccine uptake and assessing the influence of demographic, cognitive, and social factors on the incidence of COVID-19 vaccination. The study conducted Survival Analysis using a Cox proportional hazards model based on a sample of 202 Mexican-origin youth (61.39% female; Mage = 20.41) with data collected from August 2021 to January 2023 in central Texas. The results show a critical time period for vaccine uptake (i.e., in the first six months after the vaccines were publicly available), evidenced by a surge decrease in COVID-19 unvaccination probability. In addition, more positive attitudes toward the COVID-19 vaccine (Hazard ratio/HR = 1.89, 95% Confidence Interval/CI = [1.64, 2.18]), greater motivation (HR = 2.29, 95% CI = [1.85, 2.85]), higher education levels (HR = 1.52, 95% CI = [1.24, 1.86]), and fewer general barriers to COVID-19 vaccine knowledge (HR = 0.75, 95% CI = [0.60, 0.94]) were associated with greater incidences of receiving COVID-19 vaccines at any given time point during the pandemic. The findings suggest that COVID-19 vaccine uptake among Mexican-origin youth occurred primarily within the initial months of vaccines being publicly distributed. To encourage vaccination among Mexican-origin youth, sustained COVID-19 vaccine promotion efforts are needed by targeting their motivation and positive attitudes and reducing barriers to vaccine information, particularly for youth with lower education levels.