Westminster's mission work is coordinated by three committees: Local, National, and International.

Local Mission creates partnerships with community service organizations and nonprofits. Our local mission work is organized around the acronym CHESS: Children, Hunger, Education, Shelter, and Self-Sufficiency. The Local Mission Committee also sponsors the Westminster Community Grant Program, an annual award to local nonprofits to help further their missions.

National Mission currently focuses on three primary areas: housing rehabilitation in Appalachia with the Appalachia Service Project; regional hunger concerns through gleaning trips in connection with the Northern Neck Food Bank and the Society of St. Andrew; and support of Native American ministry and mission with the Bdecan Presbyterian Church in Spirit Lake, North Dakota.

International Mission works around the world through direct partnerships, through the Presbyterian Church, USA, and in cooperation with mission organizations. Westminster's international missions are primary focused on the United Orphanage & Academy in Moi's Bridge, Kenya, supported since its founding in 2001 by Westminster, Old Presbyterian Meeting House (Alexandria), and Lewinsville Presbyterian Church (McLean).