Alan Stewart Duncan (born 13 January 1965) is a British economist and econometrician.

Duncan was awarded the Frisch Medal of the Econometric Society in 2000 for the article Estimating Labour Supply Responses using Tax Reforms (with Richard Blundell and Costas Meghir in Econometrica).

He was head of the Nottingham School of Economics (University of Nottingham) from 2008 to 2010 and director of the National Centre for Social and Economic Modelling at the University of Canberra from March 2010 to January 2013.

He held positions as lecturer and then reader in economics at the University of York from 1990 to 1999.

Duncan has worked on subjects ranging from labour economics, econometrics, public policy, and education to microeconomics.