Mario White graduated from Oklahoma State in 2002 with a B.S. in math and a B.A. in history. He received the Barry M. Goldwater Scholarship and was a state finalist for the Rhodes Scholarship. He served as a tutor and senior coordinator for the Mathematics Learning Resource Center (now Mathematics Learning Success Center).
After graduation, White moved to Dallas, where he taught high school mathematics for three years. In 2005, he moved to Madison, Wisconsin, to attend law school at the University of Wisconsin-Madison. When law school was completed, he began working as an assistant state public defender and became an adjunct professor at UW Law School, where he teaches trial advocacy. A consummate trial attorney, White joined the faculty of the Wisconsin Trial Skills Academy in 2012 and the faculty of the National Criminal Defense College in Macon, Georgia, in 2017.
White has lectured at public defender agencies in New Jersey and Iowa. The Wisconsin Law Journal named him a 2017 Leader in the Law. In March 2018, after nearly 10 years with the public defender office, he took the bench as a Dane County Circuit Court Commissioner. As a commissioner, he presides over small-claims actions and family law cases.