James S. Economou is an American physician-scientist on the faculty of the University of California, Los Angeles (UCLA) where he is also a surgical oncologist and tumor immunologist.

[11][7] He has also served as a founding member of the Los Angeles Zoo Medical Advisory Board and has operated on a male silverback lowlands gorilla with a large parotid tumor, a Borneo orangutan with a laryngeal sac infection and a single-horned Indian white rhinoceros with cancer.

[17] He has chaired two National Cancer Institute Study Sections, and was continuously NIH funded for 30 years on the UCLA faculty.

[23][24] Economou is a co-founder of Kite Pharma,[25][26] a biotechnology company focused on the design and development of immune-based targeted therapies for multiple cancer indications.

On June 6, 2014, Kite Pharma announced it had entered into an exclusive, worldwide license with the National Institutes of Health (NIH).