Valenzuela was born in Concepción, Chile to American Methodist missionaries Raimundo Arms Valenzuela and Dorothy Bowie Valenzuela. He spent his childhood in Concepción where he attended primary school at the Lycée Charles de Gaulle, where he learned to speak French. In 1960, after his school was destroyed by the Great Chilean Earthquake, he was sent by his family for a year to the United States. During the next eight years, he went back to visit his family in Chile only once. He earned a B.A. summa cum laude in Political Science and Religion from Drew University and in 1971 he obtained a Doctorate and a Master's degree in Political Science from Columbia University.

Valenzuela is married to Kathryn Mudge. He has two children from his first marriage.

In 1992 Valenzuela was appointed Deputy Assistant Secretary for Inter-American Affairs in the United States Department of State by President Bill Clinton. His primary responsibility there was United States foreign policy towards Mexico. In President Clinton's second term in office, he was appointed Special Assistant to the President and Senior Director for Inter-American Affairs at the National Security Council at the White House.

On May 12, 2009 Valenzuela was nominated by President Barack Obama as Assistant Secretary of State for Western Hemisphere Affairs. The nomination was confirmed by the Senate on November 5, 2009.

Valenzuela has been a Visiting Scholar at Oxford University, the University of Sussex, the University of Florence (Italy) and the Catholic University of Chile. He has served on the board of directors of Drew University, the National Democratic Institute for International Affairs (NDI), the National Council of La Raza (NCLR) and the advisory boards of Americas Watch and the Institut des Amériques in Paris.

For his diplomatic contributions Valenzuela has been honored Brazil's Order of the Southern Cross and Colombia's Order of Boyaca.

Books

• "Political Brokers in Chile: Local Government in a Centralized Polity"
• "The Breakdown of Democratic Regimes: Chile"
• "The Failure of Presidential Democracy" (with Juan J. Linz)

Papers

• Valenzuela, Arturo. " Latin American Presidencies Interrupted" in Journal of Democracy Volume 15, Number 4 October 2004