Jonathan Evan Fielding is a board-certified physician in both Pediatrics and Preventive Medicine, and the former director and health officer of the Los Angeles County Department of Public Health. At UCLA, he is a Distinguished Professor in the Fielding School of Public Health and a Professor in the David Geffen School of Medicine. He is the founder and co-director of the UCLA Center for Health Advancement in the UCLA Fielding School of Public Health.

The UCLA Jonathan and Karin Fielding School of Public Health is the graduate school of public health at UCLA, and is located within the Center for Health Sciences building on UCLA's campus in the Westwood neighborhood of Los Angeles, California. The UCLA Fielding School of Public Health has 690 students representing 25 countries, more than 11,000 alumni and 247 faculty, 70 of whom are full-time.