Nadarajan "Raj" Chetty (born August 4, 1979) is an Indian-American economist who is the William A. Ackman Professor of Public Economics at Harvard University. Some of Chetty's recent papers have studied equality of opportunity in the United States and the long-term impact of teachers on students' performance. Offered tenure at the age of 28, Chetty became one of the youngest tenured faculty in the history of Harvard's economics department. He is a recipient of the John Bates Clark Medal and a 2012 MacArthur Fellow. Currently, he is also an advisory editor of the Journal of Public Economics. In 2020, he was awarded the Infosys Prize in Economics.

Raj Chetty was born in New Delhi, India to a Tamil family, and lived there until the age of nine. His family immigrated to the United States in 1988. Chetty graduated from University School of Milwaukee in 1997 and earned his AB from Harvard University in 2000. He continued at Harvard to earn his PhD in 2003, completing a dissertation under the direction of Martin Feldstein, Gary Chamberlain, and Lawrence F. Katz with a thesis titled Consumption commitments, risk preferences, and optimal unemployment insurance. As a sophomore in college, Chetty was told by his mentor Feldstein to pursue his own ideas after proposing a counterintuitive idea that higher interest rates sometimes lead to higher investment.

In 2003, at the age of 24, Chetty became an assistant professor of economics at the University of California, Berkeley, becoming a tenured associate professor there at 28. In 2009, Chetty returned to Harvard, where he was the Bloomberg Professor of Economics and the director of the Lab for Economic Applications and Policy. In 2015, Chetty moved to Stanford, where he became a professor in the Economics Department. In June 2018, Raj Chetty's frequent coauthor John Friedman announced that Chetty would return to Harvard. In July of the same year, he became a Founding Director of Opportunity Insights with John Friedman and Nathaniel Hendren.

In 2011 with John Friedman and Jonah Rockoff, Chetty found that test-score based value-added measures are not substantially biased by unobserved student characteristics and that the students of high value-added teachers have markedly better outcomes later in life. Drawing on these findings, Chetty testified in the landmark case Vergara v. California in support of the plaintiffs’ key points: that teacher quality has a direct impact on students’ achievements and that the current dismissal and seniority statutes have disparate impact on minority and low-income students.

Chetty is also known for research showing that economic mobility varies enormously within the United States and for work on the optimal level of unemployment benefits.

Chetty's contribution to economic mobility started with his 2014 paper, "Where is the Land of Opportunity? The Geography of Intergenerational Mobility in the United States." In this paper, Chetty discussed the effects of geography on economic mobility. He used information from deidentified federal income tax records, which gave him records from 1996 to 2012. The research's main focus was on intergenerational mobility in the United States as a whole. Chetty used the parent's income between the years of 1996-2000 when the participants were between the ages of 15–20. Chetty concluded that 5 significant variables strongly correlated with intergenerational mobility. Those variables are residential segregation, income inequality, school quality, social capital, and family structure. This concluded that intergenerational mobility is considered mainly a local problem. Meaning that place-based policies are better fitting for each city. This allows for each city to be able to make a plan and policy that will best help the people in that city that is affected by the constrictions of intergenerational mobility.

In 2020, in collaboration with the U.S. Census, Chetty worked with Hendren and Friedman to construct the Opportunity Atlas, a comprehensive Census tract-level dataset of children's outcomes in adulthood using data covering nearly the entire U.S. population. The Atlas maps the roots of affluence and poverty back to the neighborhood level, demonstrating which areas of the country offer children the best opportunities to succeed.

In 2008, The Economist and The New York Times listed Chetty as one of the top eight young economists in the world. Chetty is among the most cited young economists in the world. In 2010, he received the Young Labor Economist Award from the Institute for the Study of Labor for his paper "Moral Hazard Versus Liquidity and Optimal Unemployment Insurance" in the Journal of Political Economy.