Mary Ross-Cunningham has been a Lake County Board Member since 2002. She represents District 9, which includes portions of Waukegan and North Chicago. She was elected Board Vice-Chair in 2018 and has served in that position since.

In addition to serving as the Board Vice-Chair, Mary also serves as Chair of the Law & Judicial Committee and the Diversity & Inclusion Committee, as Vice-Chair of the Reappointment Committee, and as a member of the Health & Community Services, and Rules committees. She serves on the Lake County Community Health Center Governing Council. She has also been appointed the Vice-Chair of the Economic Development Committee and Veteran's Committee and is a member of the Illinois Membership Board for the National Associations of Counties (NACO). Her main priorities are jobs and affordable housing.

Mary enjoyed a career as a nurse for 29 years at the Veterans Administration Hospital in North Chicago, and several years working at the Great Lakes Naval Base Food Service before running for the Lake County Board. She is the second African-American woman to sit on the Board. Mary has continued to serve her community through other organizations like the Waukegan Housing Authority-Commissioner, Lake County Community Action Partnership-Board of Directors Member, Lake County Pads Homeless Shelter and more.