Janet Yellen is an American economist and the first woman to serve as the US Secretary of the Treasury, a position she held from 2021 to 2025. She was also the first woman to chair the Federal Reserve, serving from 2014 to 2018, where she played a key role in guiding US monetary policy during the recovery from the 2008 financial crisis. A former professor at the University of California, Berkeley, Yellen is known for her expertise in macroeconomics and labour markets.