During the COVID-19 pandemic, the Virtual Training Academy (VTA) was established to rapidly develop a contact-tracing workforce for California. Through June 2021, more than 10 000 trainees enrolled in a contact-tracing or case investigation course at the VTA. To evaluate program effectiveness, we analyzed trainee pre- and postassessment results using the Wilcoxon signed-rank test. There was a statistically significant (P < .001) improvement in knowledge and self-perceived skills after course completion, indicating success in training a competent contact-tracing workforce. (Am J Public Health. 2021;111(11):1934-1938. https://doi.org/10.2105/AJPH.2021.306468).