Mahlon "Sandy" Apgar IV (born 14 January 1941) is a housing, infrastructure, and real estate consultant to global corporations and government agencies, and a non-resident Senior Advisor at the Center for Strategic and International Studies (CSIS). He is known as the "father" of the US Army's housing privatization program, the largest such public-private partnership program in the Department of Defense. He was a partner and senior advisor at the Boston Consulting Group (BCG), and a partner at McKinsey & Company where he led its operations in Saudi Arabia, and a Senior Scholar at the Woodrow Wilson International Center for Scholars where he wrote the playbook on public-private partnerships.