Kyle A. Diamantas, a Florida attorney whose family roots reach back to the Greek island of Chios, is serving as Acting Commissioner of the U.S. Food and Drug Administration.
Diamantas has led the FDA since May 15, following the departure of Commissioner Marty Makary. Before taking over the agency, he headed its Human Foods Program and oversaw food safety and nutrition policy.
His tenure may be brief. President Donald Trump announced on August 19 that he was nominating White House adviser and physician Heidi Overton as the next FDA commissioner. Overton would require Senate confirmation, leaving Diamantas in charge in the meantime.
The temporary role has placed him at the center of major regulatory decisions. On August 26, the FDA approved Rasonque, a targeted treatment for metastatic pancreatic cancer. Earlier in the month, it approved Moderna’s mFlusiva for adults 50 and older, the first mRNA-based seasonal flu vaccine approved in the United States.
Diamantas’ Greek background does not appear in his official FDA biography, but The National Herald recently highlighted his family connection through his paternal grandfather, William J. Diamantas, who was born on Chios in 1932.
William Diamantas immigrated with his family to New York in the 1930s. He later attended New York University and the Columbia School of Broadcasting, served during the Korean War, and built a career in radio before settling in Florida.
Kyle Diamantas earned a bachelor’s degree in pre-law political science from the University of Central Florida and a law degree from the University of Florida Levin College of Law.
He worked at Baker Donelson before joining Jones Day’s Health Care & Life Sciences practice in Miami in 2021. His work included advising companies in the food, pharmaceutical, and consumer-product sectors on regulatory matters involving the FDA and other federal agencies. He became a partner at the firm in 2024.
That private-sector work has also drawn scrutiny since he entered government.
Diamantas represented Abbott Laboratories in litigation involving a specialized formula for premature infants and claims concerning necrotizing enterocolitis, a serious intestinal disease. Abbott has disputed claims that its preterm formulas cause NEC.
KFF Health News reported that Diamantas had a specific recusal involving Abbott after joining the government and voluntarily refrained from infant formula matters during that period. The recusal ended in January 2026.
Diamantas joined the FDA in February 2025 as Acting Deputy Commissioner for Human Foods. He later became Deputy Commissioner for Food and also served as a senior counselor within the Department of Health and Human Services.
His rise to the top of the FDA was unusually fast. Within roughly fifteen months of joining the agency, he was serving as acting commissioner.
His professional background is also different from that of many previous FDA leaders. Diamantas is a regulatory attorney rather than a physician or medical researcher.
The agency is now moving toward another leadership change, although the timing remains uncertain. For the moment, Diamantas remains at its helm, more than nine decades after his grandfather left Chios for the United States as a child.