Alexander Taghi Tabarrok (born November 11, 1966) is a Canadian-American economist and co-author, with Tyler Cowen, of the economics blog Marginal Revolution. Tabarrok and Cowen have also ventured into online education with Marginal Revolution University.

Both Cowen and Tabarrok are professors at Virginia's George Mason University and fellows with the school's Mercatus Center. In addition, Tabarrok is director of research for the Oakland, California based think tank the Independent Institute. He is the son of the late mechanical engineering professor Behrooz (Bez) Tabarrok.

His doctoral studies were done at George Mason University where he received his Ph.D. in 1994.

He has done work on dominant assurance contracts, law and economics and health economics. He has two sons named Connor and Max Tabarrok.

In 2012, David Brooks called Tabarrok one of the most influential bloggers on the right, writing that he is among those who "start from broadly libertarian premises but do not apply them in a doctrinaire way."