A lifelong resident of Franklin County, Ron O'Brien graduated from St. Francis DeSales High School. He earned his undergraduate degree in Business Administration from Ohio Dominican College and his Juris Doctorate degree from The Ohio State University, cum laude. Ron O'Brien started his legal career in the Franklin County Prosecuting Attorney's Office, as a legal intern, while a student at The Ohio State University. After graduation from law school, he was appointed as Assistant Prosecuting Attorney and later, a Senior Assistant Prosecuting Attorney. In 1978, Ron O'Brien was appointed Columbus City Prosecutor. In 1985, Ron O'Brien was elected Columbus City Attorney, and was re-elected in 1989 and 1993. He was elected to his first term as Franklin County Prosecuting Attorney in 1996, and subsequently re-elected in 2000, 2004, 2008, and 2012. He is now the longest serving Prosecutor in the history of Franklin County.
Ron O'Brien served as President of the Ohio Municipal Attorneys Association, President of the Ohio Prosecuting Attorneys Association, and the Ohio Director on the Board of Directors of the National District Attorneys Association. He served on the Governor's Drunk Driving Task Force and was appointed by the Chief Justice to serve on the Joint Task Force to Review the Administration of Ohio's Death Penalty. He has been recognized in the publication "Ohio's Top Lawyers" and received numerous professional and civic awards. He was recently nominated by his peers throughout the state of Ohio and named Ohio's Prosecutor of the Year for 2015.