Mark Nielsen currently serves as Executive Vice President and Chief Legal Officer at Frontier Communications Corporation, which reported revenues of $8.6 billion in 2018, making it America's fourth largest landline telephone company. Nielsen began his legal career in 1990 as an associate lawyer at the Hartford law firm Murtha, Cullina, Richter & Pinney, where he focused on federal and state litigation. His public service includes being a Connecticut State Representative from 1992 to 1994 and a State Senator from 1994 to 1998. Nielsen played key legal roles on staff for Mitt Romney during Romney's tenure as Governor of Massachusetts, serving as Chief Legal Counsel from 2004 to 2006 and Chief of Staff from 2006 to 2007. He is an honors graduate of Harvard College, class of 1986, and Harvard Law School, class of 1989. He resides in Ridgefield, Connecticut, with his wife and children, while also spending time in New York City.