Since its establishment in 1972, the Mercer Island Design Commission has been instrumental in advising the City Council on design-related issues in commercial, office, and multi-family residential spaces. Its core mission is to promote high-quality community design and enhance construction and maintenance practices throughout Mercer Island. The commission meets on the first Wednesday of each month, providing opportunities for public input either in person or via Zoom. Its design guidelines apply to all construction within and outside Town Center, including educational and public facilities. Composed of seven members selected for their expertise in architecture, civil engineering, and urban planning, the commission includes a majority of local residents.

Members are appointed by the City Council for four-year terms, with a focus on individuals possessing a strong design background. Residents interested in serving on the commission can submit applications through the city's website, contributing to both the aesthetic and economic vitality of the community.