
Matt Willis
Dr. Matt Willis is a physician and epidemiologist. He served as Marin County, California’s Public Health Officer from 2013 to 2024, where he declared climate change a public health crisis and led science-driven policy and open dialogue with impacted communities to build resiliency. He has served as Director of Primary Care on the Navajo Nation in Arizona, and at the CDC, where he conducted outbreak investigations in the US and abroad. He writes Your Local Epidemiologist in California, translating emerging science into health guidance for the public. His research has been published in Science, JAMA, Clinical Infectious Diseases, and MMWR. He holds an MD from Temple University, and completed his MPH and Internal Medicine training at Harvard.








