Holmes completed a BS in Biology and Spanish at the U. of Washington followed by a PhD in anthropology joint between UC Berkeley and UC San Francisco and an MD in the School of Medicine at UC San Francisco. He was part of the Physician Scientist Program in the Internal Medicine Residency at the U. of Pennsylvania and then Robert Wood Johnson Health & Society Scholar at Columbia U. He taught in the Department of Global Health and Social Medicine at Harvard U. He joined the faculty at UC Berkeley where he founded the Berkeley Center for Social Medicine, co-directed the MD/PhD Track in Medical Anthropology and was promoted to Chancellor's Professor. His research has been funded by multiple organizations, including the European Research Council and the National Science Foundation, and has received national and international awards from the fields of anthropology, sociology, geography, Latin American Studies and documentary film.

A sociocultural anthropologist and medical doctor, Holmes conducts interdisciplinary research on social hierarchies, health inequities, and the ways in which such asymmetries are naturalized, normalized, and resisted in the contexts of transnational im/migration, health care, and agricultural and food systems. He is Principal Investigator of the ERC Project "FOODCIRCUITS: Hidden Connections between Migrants and Societies" (2023 - 2028). He has received national and international awards from the fields of anthropology, sociology, geography, and Latin American Studies, including the Margaret Mead Award, the Robert Textor Prize, and the New Millennium Book Award. Beyond scholarly writing, he has written for popular media such as The Huffington Post and The Guardian, spoken on multiple National Public Radio, Public Radio International, and Radio Bilingüe radio programs, and produced an ethnographic documentary film that received multiple film awards.