Janet Louise Yellen (born August 13, 1946) is an American economist serving as the United States secretary of the treasury since January 26, 2021. A member of the Democratic Party, she previously served as the 15th chair of the Federal Reserve from 2014 to 2018. She is the first woman to hold either role. She is also a professor emerita at Haas School of Business at the University of California, Berkeley, and formerly a distinguished fellow in residence at the Brookings Institution.