The National Bureau of Economic Research (NBER) is a "private, nonprofit, nonpartisan research organization" dedicated to studying the science and empirics of economics, especially the American economy. It is "committed to undertaking and disseminating unbiased economic research among public policymakers, business professionals, and the academic community." It publishes NBER Working Papers and books. The NBER is located in Cambridge, Massachusetts with branch offices in Palo Alto, California, and New York City.

The NBER was founded in 1920. Its first staff economist and Director of Research was Wesley Mitchell. Simon Kuznets was working at the NBER when the U.S. government asked him to help organize a system of national accounts in 1930, which was the beginning of the official measurement of GDP and other related indices of economic activity. Due to its work on national accounts and business cycles, the NBER is well-known for providing start and end dates for recessions in the United States.

The NBER is the largest economics research organization in the United States. Sixteen of the 31 American winners of the Nobel Prize in Economics have been NBER associates, as well as three of the past Chairmen of the Council of Economic Advisers, including the current NBER president, Martin Feldstein. NBER research is published by the University of Chicago Press.