Amar has been a professor at both Yale Law School and Yale College since 1985 and has held various professorships, including Southmayd Professor from 1993 to 2008, Professor from 1990 to 1993, Associate Professor from 1988 to 1990, and Assistant Professor from 1985 to 1988. He also worked as a law clerk to judge Stephen Breyer, then of the U.S. Court of Appeals for the First Circuit, from 1984 to 1985. He is co-editor of a constitutional law casebook, 'Processes of Constitutional Decision-making', and has written several other books on constitutional law. Amar is a member of the Board of Directors of the Constitutional Accountability Center and the Coalition of Freedom Advisory Board of the National Constitution Center.
He was elected a Fellow of the American Academy of Arts and Sciences in 2007 and was named a Senior Scholar by the National Constitution Center in 2000. He received a BA from Yale College and a JD from Yale Law School.