John Fitzgerald is a psychologist specializing in understanding and treating addiction. He is a licensed professional counselor, certified addiction specialist, and has a masters degree in counseling psychology and a doctoral degree in systems science and social psychology.

He is on Clinical Faculty in the Department of Psychiatry at Oregon Health & Sciences University, is an Adjunct Assistant Professor in the Systems Science Graduate Program at Portland State University, and an Adjunct Instructor in the Graduate School of Education at Portland State University.

In 2007 his dissertation, A multilevel analysis of individual and organizational-level effects on staff attitudes towards use of medication in substance abuse treatment won the Patrick H. DeLeon Prize from Division 55 of the American Psychological Association. That same year he won a Junior Investigator Award from Addiction Health Services Research for work related to applying a systems approach to understanding the nonmedical use, abuse and diversion of opioid analgesic products. He is a member of the American Psychological Association and the American Academy of Health Care Providers in the Addictive Disorders.