John P. A. Ioannidis (Greek pronunciation: [iɔˈanis iɔaˈniðis]; born August 21, 1965) is a Greek-American physician-scientist, writer and Stanford University professor who has made contributions to evidence-based medicine, epidemiology, and clinical research. Ioannidis studies scientific research itself, meta-research primarily in clinical medicine and the social sciences. Ioannidis' paper on "Why Most Published Research Findings Are False" was the most-accessed article in the history of Public Library of Science as of 2020, with more than 3 million views. Ioannidis has been a prominent opponent of prolonged lockdowns during the COVID-19 situation.