King obtained an MPH in International Health from the University of Texas School of Public Health in 1994, and an MBA in International Health Management from Thunderbird, the American Graduate School of International Management in 1996. She completed her PhD in Public Health and Policy from the London School of Hygiene and Tropical Medicine in 2002.

Dr. Ariel Rosita King is known for her international health policy work, particularly with regard to HIV/AIDS, King is a founding and board member of Women Impacting Public Policy (WIPP). She is a Rotarian, and is the Washington, DC representative for the National Council of Women at the UN United Nations. She is vice-chair of the Continental Advisory Board and the Chair of the Resource Mobilisation Committee, of Social Aspects of HIV/AIDS Reliance Alliance (S.A.H.A.R.A). She has served on the Boards of Directors of the National Black Women's Health Project, Positive Art: Women and Children with HIV/AIDS in South Africa, The Life Foundation AIDS Foundation of Hawaii, The Black Alliance for AIDS Prevention, and the Ronald McDonald House. King is also a member of the board of trustees of the Acid Survivors Trust International. In 2010, she also met with Princess Anne (Anne, Princess Royal) in the United Kingdom to discuss her non-profit work.