William Poole was a senior fellow at the Cato Institute, senior adviser to Merk Investments and, as of fall 2008, Distinguished Scholar in Residence at the University of Delaware.

Prior to joining Cato, Poole was the president and CEO of the Federal Reserve Bank of St. Louis. He directed the activities of the bank's head office in St. Louis, as well as its three branches in Little Rock, Arkansas; Louisville, Kentucky;, and Memphis, Tennessee. In addition, he represented the Bank on the Federal Open Market Committee, the Federal Reserve's chief monetary policymaking body.

Before that, Poole was Herbert H. Goldberger Professor of Economics at Brown University. He served on the Brown faculty from 1974 to 1998 and the faculty of The Johns Hopkins University from 1963 to 1969. Between these two university positions, he was senior economist at the Board of Governors of the Federal Reserve System in Washington. He was a member of the Council of Economic Advisers in the first Reagan administration, from 1982 to 1985.

Poole has engaged in a wide range of professional activities, including publishing numerous papers in professional journals. He has published two books, Money and the Economy: A Monetarist View, in 1978, and Principles of Economics, in 1991. During his 10 years at the St. Louis Fed, he gave over 150 speeches on a variety of topics. In 1980–81, he was a visiting economist at the Reserve Bank of Australia and in 1991, Bank Mees and Hope Visiting Professor of Economics at Erasmus University in Rotterdam. At various times, he served on advisory boards of the Federal Reserve Banks of Boston and New York, and the Congressional Budget Office.

Poole attended Swarthmore College, receiving an AB degree in 1959. He received MBA and PhD degrees from the University of Chicago in 1963 and 1966, respectively. Swarthmore honored him with a doctor of laws degree in 1989.