Kathleen M. Mazzarella is Chairman, President and CEO of Graybar.

Ms. Mazzarella joined Graybar in 1980 in customer service and soon became one of Graybar’s top salespeople. She advanced into field sales management and later was promoted into corporate product management. At Graybar’s corporate headquarters, she held executive-level positions in strategic accounts, human re­sources, strategic planning, sales, and marketing. She was named executive vice president and chief operating officer in 2010. Ms. Mazzarella was appointed Graybar’s 11th president and CEO in 2012, and she became chairman of Graybar’s board of directors the following year.

Ms. Mazzarella holds an associate degree in telecommunications engineering, a bachelor’s degree in applied behavioral sciences and a master’s degree in business administration. She serves on the boards of Waste Management, Inc., Cigna Corporation, Core & Main LP, the National Association of Wholesaler-Distributors (NAW), Greater St. Louis, Inc., and Bogey Club. In addition, she is a member of The Committee of 200, The Business Council, the International Women’s Forum, Vistage Worldwide, Inc. and The American Cancer Society's CEOs Against Cancer of Missouri - St. Louis Chapter.

Ms. Mazzarella was recognized by the St. Louis Business Journal with the “40 Under 40” award in 2000 and as one of St. Louis’ “Most Influential Businesswomen” in 2004. In 2011, she received the Outstanding Alumna Award from the George Herbert Walker School of Business & Technology at Webster University. In 2014, Ms. Mazzarella was recognized by the Urban League of Metropolitan St. Louis as one of its distinguished women in leadership. In 2015, she earned the National Association of Electrical Distributors’ Trailblazer Award and was recognized as a Leader of Distinction by the YWCA of Metro St. Louis. In 2019, she was honored as a Junior Achievement Business Hall of Fame Laureate. Ms. Mazzarella was recognized by Modern Distribution Magazine in 2021 as one of the inaugural winners of its Women in Distribution Leadership Award. She was named to the St. Louis Titan 100 list in 2022 and 2023 and became a member of the St. Louis Titan 100 Hall of Fame in 2024