Sean M. Stack
Chairman and Chief Executive Officer
United States of America
Sean M. Stack is Aleris chairman and chief executive officer. In December 2016, he was appointed Chairman of the Board. Sean was named president and chief executive officer in 2015. He was previously executive vice president and chief executive officer, Aleris North America. Prior to that, he was executive vice president and chief financial officer from 2009 to 2014. He joined Commonwealth Industries in June 2004 as vice president and treasurer and became Aleris senior vice president and treasurer in December 2004 when the company was established upon Commonwealth’s merger with IMCO Recycling. During his tenure at Aleris, he has held roles of increasing responsibility including executive vice president, Corporate Development and Strategy, and executive vice president and president, Aleris Europe. Prior to joining Aleris, Mr. Stack served as vice president and treasurer of Noveon, Inc. beginning in March 2001. Prior to joining Noveon, he held senior level finance roles at Specialty Foods and ABN AMRO Bank. Mr. Stack holds a Masters in Management from the Northwestern Kellogg School of Management, and a Bachelors in Business Administration from the University of Notre Dame.