A native of Massachusetts, Dean Bilionis was a Morehead Scholar at the University of North Carolina-Chapel Hill, where he was elected Editor-in-Chief of The Daily Tar Heel and graduated Phi Beta Kappa with a double major in Economics and English. He graduated from Harvard Law School magna cum laude in 1982, serving on the Board of Student Advisors. Upon graduation from law school, he clerked for the Honorable Francis D. Murnaghan, Jr., of the United States Court of Appeals for the Fourth Circuit. Dean Bilionis then entered private practice with the firm of Ropes & Gray in Boston, representing major national and multinational corporations in litigation. His interest in constitutional law and commitment to the cause of equal justice led Dean Bilionis back to North Carolina, where he served for several years in the Office of the Appellate Defender as an assistant appellate defender representing indigent criminal defendants, with an emphasis on capital punishment appeals. He joined the UNC-Chapel Hill law faculty in 1988, focusing his research and teaching on diverse issues in constitutional law and criminal law, including the transformation of judicial review in the Supreme Court, the Constitution's relationship to substantive criminal law, the Eighth Amendment and capital punishment, and state constitutional law. In 1999, he was appointed the UNC's first Samuel Ashe Distinguished Professor of Constitutional Law.
In 2005, Bilionis was appointed Dean of the University of Cincinnati College of Law and Nippert Professor of Law. He is a nationally recognized scholar in the areas of constitutional law and criminal law and procedure, with his work published in leading law journals such as the Michigan Law Review, Texas Law Review, Georgetown Law Journal, University of California-Los Angeles Law Review, Emory Law Journal, North Carolina Law Review, and Law and Contemporary Problems. He has taught constitutional law, criminal law, criminal procedure, and evidence, as well as seminars on capital punishment, constitutional law and theory, criminal law and procedure, and sentencing.