Stephen Luby studied philosophy and earned a Bachelor of Arts summa cum laude from Creighton University. He earned his medical degree from the University of Texas Southwestern Medical School at Dallas and completed his residency in internal medicine at the University of Rochester-Strong Memorial Hospital. He studied epidemiology and preventive medicine at the Centers for Disease Control and Prevention. He works primarily in Bangladesh but also has projects in Western China and Liberia. 

Luby's previous positions include directing the Centre for Communicable Diseases at the International Centre for Diarrhoeal Diseases Research, Bangladesh in Dhaka, Bangladesh from 2004 - 2012, conducting research and teaching epidemiology at the Aga Khan University in Karachi, Pakistan from 1993 to 1998, and working as an epidemiologist in the Foodborne and Diarrheal Diseases Branch of the U.S. Centers for Disease Control and Prevention.