McKenna L. Cox graduated magna cum laude from Wofford College with a bachelor's degree in English, Spanish, and Latin American Studies. She holds a master's degree in Romance languages and literature from UNC-Chapel Hill and is fluent in Spanish. McKenna received her Juris Doctor from the University of Tennessee College of Law in 2005 with a concentration in advocacy and dispute resolution.

McKenna has over 17 years of experience in family law, adoption, domestic violence, mediation, powers of attorney, immigration, conservatorships, and litigation practice. She is a Rule 31-listed family mediator in the state of Tennessee. McKenna is also a graduate of the National Institute of Trial Advocacy and the Catholic Charities CLINIC program for the representation of victims of crime in immigration cases. She is a member of the American Immigration Lawyers Association (AILA), the Federal Bar Association and its Immigration Law Section, the Tennessee Bar Association, the LGBT Bar Association, and is the past vice president and pro bono coordinator of the Washington County Bar Association. She has served on the Board of Legal Aid of East Tennessee, is an appointed member of the Tennessee Supreme Court Access to Justice Commission, and serves as the chancellor for St. John's Episcopal Church in Johnson City, TN, and as the Parliamentarian and Vice-Chancellor for the Episcopal Diocese of East Tennessee 2020-2023.

McKenna has lived in multiple states in the United States as well as in Santiago, Chile, and has traveled throughout Central and South America, Spain, the Caribbean, Western Europe, Southeast Asia, Hong Kong, Egypt, and most of North America. She enjoys playing with her pet rabbit and her two basset hounds, traveling with her children and husband, photography, singing, paper crafting, and reading historical fiction.